Mechanika 2008

Mechanika, 2008

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Mechanika, 2008

Mechanika 2008 edition Editors: Ayush Arora & Rohit Mittal Designed by: Vivek Tripathi & Rohit Mittal

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MESA Faculty Adviser Dr. Sankha Deb

President Rohit Mittal

Vice President Lokesh Saini

◊ Executive Members Rohit Mittal, Lokesh Saini, Atul Kumar Soti, Ayush Arora, Atanu Bhuyan, Sushant Kumar, Rohit B. Ramtekkar, C.Kartha

◊ Publication Team Ayush Arora (Secretary), V.Rohit, Prathyusha.M, Nished Singhal, Rohit Koolwal, Deepak Shilpi, Govind Mohan, Grandhi Pradeep Kumar

◊ Activity Group Atul Kumar Soti (Secretary), D.V.Phani, Shalabh Malhotra, S Satya kalyan

◊ Website Committee Atanu Bhuyan (Secretary), Pratik Sachan, Arun Kumar Nirala, Pankaj Singh

From the President First of all my congratulations to all members of MESA for the effort they have made with the various activities organized this session.

I am pleased to see the 3rd edition of the annual magazine of MESA, MECHANIKA’08, out in the campus and want to congratulate MECHANIKA team. I am glad to see various students from B.Tech, M.Tech, Ph.D. of all years as well as Faculty members contributing to this magazine.

Articles cover different fields of Mechanical Engineering along with the experiences of final year students. Apart from this, certain things of common interest in various fields of science and technology have also been incorporated in this edition.

There has been a lot of improvement with the type of content, design and participation from the student’s community in this edition as compared to last year’s edition. Hard work should only be the motto of all members so that we successfully keep on publishing this magazine with a lot of improvement each time. I would like to thank our faculty advisor, Dr. Sankha Deb for his valuable inputs to our effort. He has been a great motivator through out this session. I would also like to take this opportunity to thank our HOD Prof. U. S. Dixit, for his valuable suggestions and motivation Finally, I am grateful to the department for the financial support.

‘Encouraging scientific spirit by spreading scientific knowledge’ is the aim of MESA. It not only strengthens the integrity among the future engineers but also provides them with the opportunity of helping out others.

With various activities around the year it has become a part of the mechanical student’s life in the campus. With the involvement of more and more students it is on the path of success.

It has a very bright future and, I wish all the very best for its future endeavours.

Suggestions from readers are most welcome and we assure you that they would be incorporated in the next edition to make this magazine more useful to them.

Volume III For the year 2008-2009

Mechanika, 2008

Rohit Mittal President, MESA

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Mechanika, 2008

MESSAGE FROM HOD

MESSAGE FROM FACULTY ADVISER

I am happy to note that the students of Mechanical Engineering Department are bringing out the third issue of the annual magazine Mechanika with a new look. The members of Mechanical Engineering Students’ Association (MESA) of Indian Institute of Technology Guwahati have put commendable efforts for the magazine. The magazine contains very interesting articles written by students and faculty members of the Department.

I am very happy to note that Mechanical Engineering Students’ Association (MESA) is publishing the third edition of its annual magazine, Mechanika. The articles published in the magazine include contributions by undergraduate and postgraduate students of the department and faculty members. It covers a range of topics including some interesting developments in science and technology as well as some research articles.

First and second issues of Mechanika have been liked very much by the readers. I am sure that the readers will like the third issue even more.

This issue contains a number of articles of general interest and a few articles on speciďŹ c topics. Students as well as faculty members have contributed for making Mechanika more informative and enjoyable.

I would like to congratulate the publication committee, the authors and the members of MESA for all their efforts in bringing out the magazine.

I would also like to express my sincere thanks to Professor U. S. Dixit, HOD and the faculty members of the department for their constant support and valuable suggestions in publication of the magazine.

I congratulate the editors, authors and members of MESA team for binging out this issue of Mechanika. I wish that Mechanika may receive the love of the readers and motivate the authors for contributing in this magazine.

Prof. Uday Shankar Dixit Head of Deaprtment Department of Mechanical Engineering

Mechanika, 2008

Dr. Sankha Deb Assistant Professor Department of Mechanical Engineering

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Inside 48

COVER STORY 05

Emission Trading: Indian Scenario on Carbon Credits

Yearbook: Final year students What passing out seniors want to convey to juniors?

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Alumni Speaks - Rahul Swarnkar He was the first president of MESA.

Rare Breed ‘Cars’

Cable-Stayed Bridge

Page 9

Page 11

Most Powerful Diesel Engine

The Space Elevator

Page 14

Page 18

Theory for Everything

Science in the Lap of Spirtuality

Page 21

Page 31

SCIENCE & TECHNOLOGY

SURVEY

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Change of Identity Why Pluto is no more a planet?

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Rare Breed - Cars

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Cable-stayed Bridge

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Most powerful Diesel Engine

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Nano Car

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The Space Elevator

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When Compasses point south

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Theory for Everything

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The Automated Guided Vehicle It is a mobile robot used in industrial applications to move materials around.

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OFF CAMPUS 29

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Science in the Lap of Spirtuality

Campus Placement Report for (2007-08) Session What are the stats of the placement in this session?

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Gear up for Interviews How to crack PI?

RESEARCH 38

Two-phase flow instabilities in flow boiling in microchannels

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Finite Element Analysis of Mixed Mode Fatigue Crack Growth Problems

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Vibration Problems of the Primary Limestone Crusher Unit, a Case Study

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M.Tech. Projects Allotted for 2007-08 session

Gourami Business Challenge What are the different ways to get in Royal Dutch Shell?

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PLACEMENTS

Perimeter Security Systems Bollards are one of the most effective equipments which provide both visibility and high security.

We usually see various types of surveys in magazines & newspapers on politics, cricket but here it is different. Want to know more?

Mechanika, 2008

cover story

EMISSION TRADING INDIAN SCENARIO ON CARBON CREDITS

by Vijaya Kumar Pantangi

KYOTO PROTOCOL Kyoto Protocol (KP) is an agreement made under the United Nations Framework Convention on Climate Change (UNFCCC).

The very phrase ‘Kyoto Protocol’ has become synonymous with the idea of saving the planet from global meltdown.

The UNFCCC divides the member countries into two main groups: A total of 42 industrialized countries are currently listed in the Convention’s Annex-I, including the relatively wealthy industrialized countries that were members of the Organization for Economic Co-operation and Development (OECD) in 1992, plus countries with economies in transition (EITs), including the Russian Federation, the Baltic States, and several Central and Eastern European States. The OECD members of AnnexI (not the EITs) are also listed in the Convention’s Annex-II. There are currently 23 such Annex-II Parties.

All other countries not listed in the Convention’s Annexes, mostly the developing countries, are known as Non-Annex-I countries. They currently number 145.

The convention covers all Green House Gases (GHG’s) not covered by the 1987 Montreal Protocol to the United Nations Convention on protection of the Ozone layer. The target gases are mainly six: Carbon Dioxide (CO2), Methane (CH4), Nitrous Oxide (N2O), Hydroflourocarbons (HFC’s), Perflourocarbons (PFC’s) and Sulpur Hexaflouride (SF6). The KP aims to tackle global warming by setting target levels for nations to reduce GHG’s worldwide. These targets vary between regions and countries but globally the initial target is to reduce GHG’s level by 5.2 below 1990 levels (base levels) during the 2008-2012 period.

The Kyoto protocol broke new grounds with three innovative and flexible mechanisms: Joint Implementation (JI) JI is a project based mechanism developed under the KP, designed to assist countries in meeting their emission reduction targets through joint projects with other countries. That means JI projects can only be implemented between capped industrialized countries. One or more investors (governments, companies, funds etc.) will agree with partners in a host country to participate in project activities which generate Emission Reduction Units (ERU’s), in order to use them for compliance with targets under the KP.

Mechanika, 2008

Global Warming “save our planet” One of the environmental threats our planet faces today is the potential for long-term changes in the earth’s climate and temperature pattern known as “Global Climate Change”. Scientists estimate that as a result of global climate change, the earth’s average temperature could increase as much as six and a half degrees Fahrenheit by the year 2100. During the last ice age, when our planet was on average only nine degrees Fahrenheit cooler, the area that is now New York city was under 1000 feet of ice and this shows how much effect these global climatic changes can have on the natural and human systems of earth.

The consequences of global warming are innumerous with the very beginning affecting the human health, sea level, life cycles of each and every living being. The Inter Government Panel on Climate Change (IPCC) projects a sea level increase of six inches to more than three feet by the year 2100. Droughts, floods and storms could become more severe and entire agricultural regions could become disrupted as rainfall and temperature patterns shift. This also results a large gap between demand and production of food crops and finally one has to compete with each other for these in a different environment which is beyond the imagination.

To prevent this sort of disruption, an important step was made in 1995 when over 2500 scientists from around the world agreed for the first time that emissions of Green House Gases (GHG’s) from human activities have influenced the global climate. Again on 11 December, 1997 a new treaty at the 3rd conference of the parties held in Kyoto, Japan called Kyoto Protocol was agreed. It entered into force on 16 February, 2005.

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cover story

Emission from host country are limited under the KP; JI projects reduce emissions in the host country and free up part of their total amount (assigned amount) which can than be transferred to the investor country in the form of ERU’s, which are subtracted from the host country’s allowed emissions and are added to the total allowable emissions of the investor country. Projects started in 2000; however, ERU’s can only be used for compliance from 2008, even in the European Union Greenhouse Gas Emission Trading Scheme (EU ETS).

The Clean Development Mechanism Under the Clean Development Mechanism (CDM), a developed country can ‘sponsor’ a greenhouse gas reduction project in a developing country where the cost of GHG reduction project activities is usually much lower, but the atmospheric effect is globally equivalent. The developed country would be given credits for meeting its emission reduction targets, while the developing country would receive the capital investment and clean technology or beneficial change in land use.

The CDM is a mechanism established for project based emission reduction activities in developing countries. The CDM is designed to meet two main objectives: to address the sustainable development needs of the host country and to increase the opportunities available to Parties to meet their commitments.

The CDM Project cycle comprises seven steps: • Submission of the project design document to the national CDM Authority • Project registration in the host country • Project validation and registration by the executive board of the UNFCC • Project monitoring by the host country • Verification and certification • Issuance of Certified Emission reductions (CER’s) • Revalidation of the undergoing projects for extended crediting periods. Consultants for validation of the CDM projects are: Pricewaterhouse Coopers, DNV, Ernst & Young, TERI and WIN ROCK. “A

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International Emission Trading

“Carbon Trading” Under International Emissions Trading (IET), countries can trade in the international carbon credit market to cover their shortfall in CER’s. Countries with surplus credits can sell them to countries with capped emission commitments under the Kyoto Protocol.

Carbon credits are generated by enterprises in the developing world that shift to cleaner technologies and thereby save on energy consumption, consequently reducing their GHG emissions. For each CER unit (the major GHG) emission avoided, the entity can get a carbon emission certificate which they can sell either immediately or through a futures market, just like any other commodity. The certificates are sold to the entities in rich countries, like power, utilities, which have emission reduction targets to achieve and find it in cheaper to buy ‘offsetting’ certificates rather than do a clean-up in their own backyard. This trade is carried out under UNFCC to help rich countries reduce their emissions.

Emission trading is a general term used for the three KP flexibility mechanisms. It is a market based system that allows the firms the flexibility to select cost-effective solutions to achieve established environmental goals. These flexibility mechanisms include the use of Carbon Sinks (pools that take up released carbon from another part of the carbon cycle) and emissions trading. Under the Protocol a planted forest which is established after 1st January 1990 on previously cleared land will count as carbon sink. The carbon dioxide sequestered in such a forest can be used to create carbon credits. Carbon credit as defined by KP, is one metric ton of carbon (t CO2) by the burning of fossil fuels.

The other target GHG’s are also can be converted into carbon credits with an internationally agreed ‘Global Warming Potential’ (GWP) assigned to them.

These GWP factors are used to convert each of the major GHG’s that are not carbon dioxide into tones of equivalent carbon dioxide (t CO2eq) which is a standard unit for the trading.

The prices of the credit ranges hover around 22 Euro per t CO2 in 2005. In 2004, 107 mt CO2 were exchanged through green projects, a 38% rise from 2003.

CER unit is equivalent to one tonne of CO2”

Mechanika, 2008

cover story

Indian Scenario India comes under the third category of signatories, i.e. Non-Annex-I, to UNFCCC. India signed and ratified the Protocol in August, 2002 and has emerged as a world leader in reduction of GHGs by adopting Clean Development Mechanisms (CDM’s) in the past few years. Being a developed country it is exempted from the requirement of adherence to the protocol. This serves three purposes: 1. Avoids restrictions on growth because pollution is strongly linked to industrial growth, and developing economies can potentially grow very fast.

2. It means that they cannot sell emissions credits to industrialized nations to permit those nations to over-pollute.

3. They get money and technologies from the developed countries in Annex II. Companies that invest in bio-diesel, windmills co-generation and bio-mass are the huge generators of carbon credits in India. There is a great opportunity awaiting India in carbon trading which is estimated to go up to $100 billion by 2010. According to a recent World Bank Survey, the country could emerge as one of the largest beneficiaries accounting for 25% of the total world carbon trade as the countries like US, Germany, Japan and China are likely to be the biggest buyers of carbon credits.

The major sources of GHG’s emission in India other than industries and transportation are as follows:

Table 1: List of few Indian firms, acquired carbon credits and their money value Companies

Project

CER’s (Units)

Value in Money (INR Crores)

Torrent Power AEC

Energy Efficiency

11900572

199.9

Gujarat Flouro Chemicals

Gas Capture

3380076

56.8

Indian Aluminium

Gas Capture

2553344

42.9

Lanco group

Fuel switching

2289478

38.5

Jaypee Associates

Energy Efficiency

1084469

18.2

Chennai Petroleum Refineries

Energy Efficiency

1010000

17.0

Balrampur Chinni

Renewables

936289

15.7

Jindal Vijayanagar Steels

Energy Efficiency

575967

9.7

Orissa Sponge Iron

Energy Efficiency

424549

7.1

Kalpataru Power Transmission

Renewables

313743

5.3

Paddy fields: The emissions from the paddy fields can be reduced through special irrigation strategy and appropriate choice of cultivars and a major break through is already done by the scientists at the University of Agricultural Sciences (UAS), Bangalore. They have developed a new rice variety called “Aerobic Rice“ that consumes 50% less water than conventional types and precludes release of methane. The intensive roots of this variety help in better absorption of water thereby eliminating the need for water logging and nonmethane emitting capabilities is hoping to get carbon credits. It has been developed by Prof H. E. Shashidhar and the team from Dept of Genetics and Plant Breeding, UAS, Bangalore.

Enteric fermentation from cattle and buffaloes: In case of enteric fermentation emission, it can be reduced through proper feed management.

Municipal Solid Waste: The last and the least preferred one, municipal solid waste, is a huge potential for the GHG’s emission in India and requires a lot more scientific approach to treat them with compliance of regulations.

Mechanika, 2008

REFERENCES • http://en.wikipedia.org/ • http://www.hinduonnet.com/

• http://www.ipcc.ch/ • http://unfccc.int/2860.php

• Sachin Trivedi, “Global Warming and Kyoto protocol: Indian Scenario on carbon credits”, Conference proceedings of Green Power 5 – International conference on Development, Management of resources and Energy Security, Feb 2-3, 2006, 398-415.

• National Solid Waste Association of India and Environmental Information System Center, News letter, Seventh Issue, February 2007.

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science & technology

Change of Identity a journey from planet to dwarf planet

by Rohit Mittal

Pluto

which till now, was better known as the ninth and the smallest planet of our solar system is no more a planet. On August 24, 2006, International Astronomical Union (IAU) for the first time defined the term ‘Planet’ due to which it is now known as a Dwarf Planet and is the second largest body in this category. On September 13, 2006, the IAU included Pluto in their Minor Planet Catalogue and gave the number 13430.

Pluto was discovered by ‘Clyde W. Tombaugh’ in February 18, 1930.

The name Pluto was first suggested by Venetia Burney, an elevenyear-old schoolgirl in Oxford, England. It is the tenth-largest body observed directly orbiting the Sun. It has three known natural moons: Charon, Nix and Hydra.

In 2006, IAU passed a resolution that created an official definition for the term Planet. According to this resolution, there are three main conditions for an object to be considered a Planet. While other planets satisfy all the above three conditions, Pluto fails to meet the third condition.

IAU Resolution The object must be in orbit around the Sun.

The object must be massive enough to be a sphere by its own gravitational force. More specifically, its own gravity should pull it into a shape of hydrostatic equilibrium.

It must have cleared the neighbourhood around its orbit, meaning it has become gravitationally dominant, and there are no other bodies of comparable size other than its own satellites or those otherwise under its gravitational influence.

Its mass is only 0.07 times that of the mass of other objects in its orbit, on contrary, Earth’s mass is 1.7 million times the remaining mass in its own orbit.

The small mass and great distance of Pluto from Earth presents significant challenges for the explorers in studying more about Pluto.

First serious attempt was made in 1977 with Voyager I. It could have visited Pluto, but was able to reach Jupiter and Saturn only.

After 29 years i.e. on January 19, 2006, a new mission targeted to Pluto was launched named New Horizons. New Horizons will use a remote sensing package that includes imaging instruments and a radio science investigation tool, as well as spectroscopic and other experiments, to characterize the global geology and morphology of Pluto and its moon Charon. It will map their surface composition and analyze Pluto’s neutral atmosphere and its escape rate. It will also photograph the surfaces of Pluto and Charon.

Its closest approach to Pluto will be on July 14, 2015. So wait for that day to know more about one of the most controversial Planet oh! sorry, Dwarf Planet.

Table shows the comparison of physical properties of Pluto and Ceres (both dwarf planets) with Earth

Mean Radius Surface area Volume Mass Density

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Pluto

Earth

Ceres

A Dwarf Planet

A Planet

A Dwarf Planet

6,371.0 km 1,195 km 7 510,072,000 km² 1.795×10 km² 1.0832073×1012 km³ 7.15×109 km³ (1.305 ± 0.007)×1022 kg 5.9736×1024 kg 5,515.3 kg/m³ 2.03 ± 0.06 g/cm³

475 km NA NA 9.46 ± 0.04×1020 kg 2.077 ± 0.036 g/cm³

Mechanika, 2008

science & technology

Rare Breed They are fast and out of the world

by Alok Verma Buggati Veyron

It is said that one man’s luxury is another’s banality. The words find meaning no where better than the world of “Ultra” cars. These cars are built to eat miles of the highways with a blink of an eye. They have body that is ravishingly stunning and they are stupendously expensive. This most elite stratum in the world of automobiles is currently occupied by Bugatti Veyron and Lamborghini’s Reventon.

Bugatti Veyron

Lamborghini Reventon

It has held the position of being the fastest and most expensive production car for 3 years now.

Equipped with an engine that churns out a whopping 1,001 Bhp, it has recorded speed of 253 mph (408.47 km/h). 10 radiators work continuously to keep this beast cool. The 8 litre, 16 cylinder engine is fed by 4 turbochargers. If still your jaw has not dropped to the ground fancy this, the car can be brought to rest from highest speed in just 10 seconds.

The car was introduced in 2007 Frankfurt Auto Show. Since then the car has invaded Bugatti Veyron’s territory with its badge of $1.4 million. The car easily attains the speed of 224 mph, thanks to 650 Italian Horses locked inside it. It has a 6.5 liter, V12 engine. The styling of the car is inspired

by F-22 stealth bomber. Its angular body frame has earned it a reputation of the sexiest looking car in the world. The car is a god-send for all those who want to feel like a fighter pilot without leaving a foot off the ground.

To put things in perspective consider this: a normal supercar (Porsches, Ferraris) have one turbocharger and at max 2 radiators. The speed of 253 mph is enough to zoom past a Formula 1 car.

The gearboxes of the Formula 1 cars need to be changed in 2 races, while Bugatti gearbox is designed to last 20-25 years.

At a price tag of $1.7 million, Veyron promises to dig a gigantic crater in bank account of anyone who fancies of buying one.

Unlike the shiny finish of super cars, Reventon has a matte skin, that too grey-green. The driver is housed in a pilot like seat with LCD instrument panel.

Both these cars are mid engined i.e the engine is placed between the front and rear wheels. Both are four wheel drive to have enough grip.

“Art is I, Science is we”

Mechanika, 2008

- Claude Bernard

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science & technology

It’s not all rosy…

Ultra car is a new breed of cars, but sadly the future looks bleak for this exotic breed. The reasons are many fold:

Fuel Consumption: These cars consume a lot of fuel. Bugatti for instance has a 100 litre tank and flat out it can run dry in 12 minutes.

Expensive to Produce:

Taking a car to such a high speed requires a whole new technology. This requires time & money. Both of these are prized commodity in an environment where there is cut-throat competition among automobile manufacturers and numerous money minded share holders. Volkswagon invested 5 million Euros to produce Veyron.

Lamborghini Reventon

Carbon emission: The CO2 per km emitted by these cars is about 10-12 times the normal cars and 4-5 times that of super cars. Lamborghini Reventon spews out 1 kg of CO2 per km. The recent change of attitude around the world towards carbon emission, tighter norms, signing of Kyoto Protocol etc. may tighten the noose just tight enough that these rare breeds may suffocate to an unfortunate death.

There has been a U-turn in the past decade’s headlong pursuit of horsepower and size. Alternate technologies like Fuel cells, Hybrid cars, Biodiesel, Solar cars etc. which not long time back were frowned upon, are now being embraced with open arms.

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EU is all set to tighten its carbon emission limit to 130 gm/km. Trans Atlantic, things are slowly getting into grooves, CAFE (corporate average fuel efficiency) is expected to rise to 35 mph from the current 27.5 mph. The Energy Policy Act of 2005 requires that 7.5 billion gallons of renewable biofuel be blended into petrol by 2012.

The big cars are giving way to small cars. Fuel efficiency instead of Bhp is the buzzword now. Only time will tell, whether Bugatti Veyron and Lamborghini Reventon are headed to become the memorabilia of an era of big, fuel guzzling, powerful and really fast cars. Till then, I keep my fingers crossed.

Mechanika, 2008

“A typical cable-stayed bridge is a continuous girder with one or more towers erected above piers in the middle of the span. From these towers, cables stretch down diagonally and support the girder” A

cable-stayed bridge is a bridge that consists of one or more columns (towers or pylons), with cables supporting the bridge deck. They can be distinguished by the number of spans, number of towers, girder type, number of cables, etc.

by Rohit Mittal

Cable-Stayed Bridge

science & technology

Different types of cable arrangments used are mono, harp, fan, and star arrangements as shown in the figure. In some cases, only the cables on one side of the tower are attached to the girder, the other side being anchored to a foundation or other counterweight.

Mono

Harp

Fan

Star

the bridge. The tension on the cables must be transferred to the earth by the anchorages, which are sometimes difficult to construct due to poor soil conditions.

Single

Double

Portal

A-shaped

Typical towers used are single, double, portal, and A-shaped towers

Comparison with suspension bridge A multiple-tower cable-stayed bridge may appear similar to a suspension bridge, but in fact is very different in principle and in the method of construction. In the suspension bridge, a large cable is made up by “spinning” small diameter wires between two towers, and at each end to anchorages into the ground or to a massive structure. These cables form the primary load-bearing structure for the bridge deck. Before the deck is installed, the cables are under tension from only their own weight. Smaller cables or rods are then suspended from the main cable, and used to support the load of the bridge deck, which is lifted in sections and attached to the suspender cables. As this is done the tension in the cables increases, as it does with the live load of vehicles or persons crossing Mechanika, 2008

In the cable-stayed bridge, the towers form the primary load-bearing structure. A cantilever approach is often used for support of the bridge deck near the towers, but areas further from them are supported by cables running directly to the towers. This has a disadvantage, compared to the suspension bridge, that the cables pull to the sides as opposed to directly up, requiring the bridge deck to be stronger to resist the resulting horizontal compression loads; but has the advantage of not requiring firm anchorages to resist a horizontal pull of the cables, as in the suspension bridge. All static horizontal forces are balanced so that the supporting tower does not tend to tilt or slide, needing only to resist such forces from the live loads.

Suspension Bridge 11

science & technology Key advantages of the cable-stayed brudge over suspension form are as follows: • much greater stiffness than the suspension bridge, so that deformations of the deck under live loads are reduced.

• can be constructed by cantilevering out from the tower - the cables act both as temporary and permanent supports to the bridge deck.

• for a symmetrical bridge (i.e. spans on either side of the tower are the same), the horizontal forces balance and large ground anchorages are not required.

• any number of towers may be used. However, a suspension bridge is usually built only with a pair of towers.

There are a number of cable-stayed bridges all over the world. The longest cable-stayed bridge is currently under construction in China and is called Hangzhou Bay Bridge.

Hangzhou Bay Bridge China The 36 km long Hangzhou Bay Bridge will be the longest ocean-crossing bridge in the world, spanning across the Hangzhou Bay on the East China Sea and crossing the Qiantang River at the Yangtze River Delta. Preparatory work started on the bridge as far back as 1994. Construction work began in June 2003 and completion is scheduled for 2008.

The S-shaped Hangzhou Bay Bridge will be an important connection in China’s East Coast Superhighway. Starting at Jiaxing to the north, the bridge will end at Ningbo to the south. It will shorten the ground transportation distance from Ningbo to Shanghai by 120km and travel time from four hours to two hours. It will be a six-lane, two-direction highway with a 100km/ hr speed limit, and a 100 year, service guaranteed, cable-stayed design.

“When opened to the public in 2009, it is estimated that the bridge will carry 45,000 to 50,000 vehicles per day in its first year of operation” “Designed for 100 years of service life, the bridge has speed limits of 100 km/h for the main spans and 120 km/h for land approaches”

Architecture, Design and Structure The cable-stayed bridge design was selected for the project as it can withstand the adverse conditions, multi-directional currents, high waves, and geologic conditions at the site.

The bridge structure has also been designed to seismic criteria and will retain integrity in earthquake conditions up to seven on the Richter scale.

The 36 km length will be of highway-class road with six, 3.75 m lanes, three in each direction. The overall width of the bridge will be 33 m. The bridge has a height of 62 m, enabling fourth and fifth generation container ships to pass through in all conditions. The total length of cable used in the project will be 32.2 km.

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“A temporary 10 km trestle has been erected for pile driving and pier construction. Each previously erected span will serve as the deck for transportation and erection of the next girders as the launching gantry moves forward”

Mechanika, 2008

science & technology

Bridge Layout and Structure The Hangzhou Bay Bridge consists of nine sections. The first one is the bank lead road to the north approach. The north approach rests on low piers with post-tension concrete boxgirder spans spanning pre-stressed continuous concrete box-girders and drill-shaft pile. The north approach leads to the north navigable bridge; a cable-stayed bridge with twin diamond-shaped towers, double cable and steel boxgirders. The main span of the north approach is 448 m.

Including side spans, the total length is 908 m. The north high piers have continuous, 70 m, post-tensioned, concrete box-girder spans with a total length of 1,470 m. The middle bridge approach is laid on low piers with 70 m, post-tension, concrete box-girder spans with a total length of 9,380 m.

The south navigable bridge is a cable-stayed bridge with an A-shaped single tower, double-cable and steel box-girders.

The main span is 318 m, and the total length including side spans is 578 m. The south high piers have continuous 70 m, post-tension, concrete box-girder spans with a total length of 1,400 m.

The eighth section measures to a total of 19,373 m, and is composed of three sections: 1. 6,020 m in-water section with 70 m girders and steel piles 2. 10,100 m mud-flat section with 50 m girders and drill-shafts 3. 3,253 m land section with 30 m to 80 m girders and drill-shaft foundations The ninth section is Bank Lead Road at the south approach.

Construction Challenges One major challenge faced by the project was the eruption of natural gas in a shallow layer along the bridge line. A special study was conducted and exploration was performed to investigate the distribution of the gas and the property of the soil during and after releasing the gas. The gas was released before pile driving to avoid any disturbance to the soil, collapsing of ground or eruption and flaming of gas.

Construction on mudflats near the south shore, in an alternating wet and dry tidal area, presented serious technical problems. A temporary 10 km trestle has been erected for pile driving and pier construction. Girders weighing 1,430 ton erected from the top, starting from the land end and launching towards the sea. Each previously erected span serve as the deck for transportation and erection of the next girders as the launching gantry moves forward.

Also, severe marine conditions caused difficulties in anchoring barges and construction vessels. Under turbulent tidal flow and typhoon influences, water flow currents are in the range of 2 m/s to 3.32 m/s at the Hangzhou Bay Bridge sites. The floating cranes can safely transport the 2,000 tons of girder from the shore to the site and then anchor stably to erect and install the precast concrete box girder.

Mechanika, 2008

“Construction work on the Hangzhou Bay Bridge began in June 2003 and completion is scheduled for 2008”

REFERENCES • http://en.wikipedia.org/wiki/Cable-stayed_bridge • http://www.roadtraffic-technology.com/projects/ •

hangzhou/index.html#hangzhou1 http://www.matsuo-bridge.co.jp/english/bridges/ basics/cablestay.shtm

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science & technology Wartsila Sulzer RT-flex96c COURTESY: www.wartsila.com

Most Powerful Diesel Engine

by Nished Singhal

T

he Wartsila Sulzer RT-flex96C turbocharged two stroke diesel engine is the most powerful diesel engine in the world. It was developed by Wartsila Corporation, a Finnish manufacturer of large diesel engines and power plants.

Courtesy: www.wartsila.com Wartsila Sulzar RT-flex96c

The needs for such powerful and large diesel engines have arisen due to the new generation of large container ships which need bigger engines to propel them. Most ship owners prefer single propeller designs.

The 14-cylinder RT-flex96C has been considered a major breakthrough in ship propulsion as it combines the high power output (around 80,080 kW) with complete flexibility of RT-flex Common Rail technology along with benefits of proven, reliable engine design.

A DIESEL ENGINE A diesel engine is an internal combustion engine which operates using the diesel cycle named after its inventor, German engineer Rudolf Diesel. Diesel engine uses compression ignition process in which the air is compressed in the compression chamber and then the fuel is injected causing the fuel to self ignite. The underlying principle is that if the air is compressed to a high degree its temperature will rise to a point sufficient to burn the fuel on contact.

Courtesy: www.sailingscuttlebutt.com

AMAZING FACTS ABOUT WARTSILA SULZER RT-FLEX96C • It was designed in Finland and made in Korea.

• It runs more efficiently than most car engines.

• The fuel consumption is about 0.26 lbs/hp/hr.

Most automotives and small engines have fuel consumption in the range of 0.4 to 0.6 lbs/hp/hr.

• It runs at more than 50% thermal efficiency and has lesser toxic emissions.

• The diametrical cylinder linear wear is only 0.03 mm per 1000 hours.

• The 14 cylinder RT-flex96C consumes about 1660 gallons of heavy fuel oil per hour.

• It was first used aboard the Emma Maersk in September, 2006.

• Out of total engine weight of 2300 tons, the crankshaft alone weighs 300 tons.

EMMA MAERSK (ship on which wartsila sulzer rt-flex96c was used)

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science & technology

WHY CROSSHEAD BEARINGS? In normal automotive engines, the connecting rod is directly attached to the piston, whereas in RT-flex96C, there is a crosshead which connects them. The crossheads are used for numerous reasons. Firstly, the sideways forces produced by connecting rod are absorbed by crosshead and not by piston. The sideways forces are the causes why the cylinders in an auto engine get oval shaped over time. Thus, the cylinder wear is reduced. It also separates the combustion area from the crank case oil which stays clean from combustion products. Lastly, it serves as a cushion the pistons as they approach the bottom dead centre to remove some load from the bearings.

Cortesy: www.people.bath.ac.uk

TECHNICAL DETAILS Total engine weight Height Length Power Maximum Power Cylinder bore Piston stroke Speed Volume displaced Fuel consumption at maximum economy Maximum torque

2300 tons 44 feet 89 feet 5720 kW per cylinder 80,080 kW (108,920 bhp) 38 inches Just over 98 inches 92-102 rpm 111,143 cubic inches per cylinder (1820 litres per cylinder) 0.26 lbs/hp/hour 5,608,312 lb/ft running at 102 rpm

COMMON RAIL TECHNOLOGY Common rail direct fuel injection (known as CRDi) is a modern variant of direct injection system for diesel engines. It features a high-pressure (1000+ bar) fuel rail feeding individual solenoid valves, as opposed to low-pressure fuel pump feeding pump nozzles or high-pressure fuel line to mechanical valves controlled by cams on the camshaft. Third generation common rail diesels now feature piezoelectric injectors for even greater accuracy, with fuel pressures up to 180 MPa / 1800 bar.

EFFICIENCY It has the best Specific Fuel Consumption efficiency among piston engines. It runs at more than 50% thermal efficiency. It emits fewer exhaust carbons per gallon of fuel burnt, making an eco-friendly engine.

REFERENCES • • • •

Mechanika, 2008

http://www.wikipedia.org/ http://www.gizmag.com/ http://www.associatedcontentcom/ http://www.wartsila.com/

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science & technology

Nano-Car Courtsey: Y. Shirai/Rice University

R

ice University scientists have developed the world’s first single-molecule car which contains a rigid chassis, four alkynes’ axles that spin freely and swivel independently, four wheels made up of p-carborane (spherical molecules of carbon, Hydrogen and boron containing 60 atoms apiece) and utilizes nanotechnology practically for all functions. It is a small coupe, with a wheel base of less than 5 nanometer, which does not have any plush seating or conventional steering system. The entire car measures just 3-4 nanometers across, making it slightly wider than a strand of DNA. About 20,000 of these nanocars could be parked, side by side, across the diameter of human hair.

The nano car’s chassis and axles are made of well-defined organic group with pivoting suspension and freely rotating axles. The axle and chassis are synthesized via palladium-catalyzed coupling reactions. It was found that nanocar was quite stable on the flat gold surface so car was driven on a gold microscopic highway and this surface was used to prevent the nanocar actually roll around its fullerene wheels rather that slipping, until the surface was heated above 170oC – presumably because of strong adhesion between the fullerene wheels and underlying gold. Between 170oC and 225oC, the car moved around by translational motion in a direction perpendicular to the handcar’s axle, indicating its motion by rolling rather than sliding. This was engineless model which could be powered remotely using a heated gold surface to stop its wheels from sticking and an electromagnetic field to drag it forwards.

Recently researchers have installed molecular engine into a “car” just a few billionth of a meter long to propel itself, using a motor entirely by light, measuring just 3 by 4 nanometer.

Courtsey: T. Sasaki/Rice University

Courtsey: Y. Shirai/Rice University

World’s First Single-Molecule Car

Two motorized nanocars on gold surface

by Lokesh Saini

A computer model shows the molecular engine in action

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science & technology

The nano-car’s molecular motor contains a pair of bonded carbon molecules that rotate in one direction if illuminated by a specific wavelength of light. After fixing the molecular engine to the car’s chassis and shining light on it, it was confirmed that engine was running using nuclear magnetic resonance to monitor the position of the hydrogen atoms within it.

The development bodes opening new vistas and we can transport molecular cargo as well as a light-driven motorized nanocar.

These images describe the basic concepts of the motorized nanocar

Courtsey: Y. Shirai/Rice University REFERENCES www.media.rice.edu www.technology.newscientist.com

“One machine can do the work of fifty ordinary men. No machine can do the work of one extraordinary man” - Elbert Hubbard

Mechanika, 2008

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science & technology

Courtsey: www.blog.speculist.com

The Space Elevator

by Deepak Shilpi

Gone are the days when there was loud roar of rocketry and bone jarring liftoffs, the time has come to make way for the project of greatest height, THE SPACE ELEVATOR. A concept imagined way back in the 1960’s, the researchers are gathering momentum in their pursuit to propel this uplifting concept into actuality.

The space elevator in simplest terms is a ribbon, one end attached to earth, the other end attached to a counterweight in outer space.

The rotation of the earth throws the counterweight on the ribbon outward keeping the ribbon taut. The counterweight spins around the Earth, keeping the cable straight and allowing the robotic lifters to ride up and down the ribbon.

A space elevator made of a Carbon Nano-Tubes Composite Ribbon anchored to an offshore sea platform would stretch to a small counterweight approximately 62,000 miles (100,000 km) into space. Mechanical lifters attached to the ribbon would then climb the ribbon, carrying cargo and humans into space.

Space Elevator

HOW IT CAN BE BUILT?

THE PROBLEM “CABLE MATERIAL” The only reason why this project had remained only a fictitious idea for over 40 years was to find a material that is super strong. The answer arrived in the form of carbon nanotubes composite ribbons. Carbon nanotubes have the potential to be 30 times stronger than steel and are as flexible as plastic. The strength of carbon nanotubes comes from their unique structure, which resembles soccer balls.

THE RIBBON Made from an advanced carbon nanotube composite material 30 times stronger than steel, the ribbon is 3 feet wide and thinner than a sheet of paper. Then vehicles climb the ribbon from earth to outer space. Simple electric motors hold the climbers upwards. Power is supplied from a ground station in form of a laser beam which is converted into electricity. The ground station can be very similar to an oil platform.

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Once a long ribbon of nanotubes is created, it would be wound into a spool that would be launched into orbit. When the spacecraft carrying the spool reaches a certain altitude, perhaps Low Earth Orbit, it would begin unspooling, lowering the ribbon back to Earth.

At the same time, the spool would continue moving to a higher altitude. When the ribbon is lowered into Earth’s atmosphere, it would be caught and then lowered and anchored to a mobile platform in the ocean.

The ribbon would serve as the tracks of a sort of railroad into space. Mechanical lifters would then be used to climb the ribbon to space.

BUILDING THE IMPOSSIBLE The elevator is a concept that does require a lot of research work like studying the effects of lightening, weather conditions on the nanotubes, wind and clouds. Space elevators to go to other worlds are also being thought of. For some the concept may sound impossible and far-fetched, but one thing is to be kept in mind that building the impossible is one thing that human knows very nicely.

REFERENCES www.physicspost.com www.science.howstuffworks.com

Mechanika, 2008

science & technology

WHEN COMPASSES POINT SOUTH!!!!

by Govind Mohan

We have had several visits above the earth, hundreds of satellites have been sent to space, dozens had trips to the moon and many are planning to visit the Mars but no one has ever dared to go beneath the earth. Yet what happens there affects every day of our lives. The Earth’s molten core is around 2,000 miles beneath our feet. Here a vast ocean of liquid iron generates an invisible force, the Earth’s magnetic field. It’s what makes our compasses point north.

Having witnessed the powerful Boxing Day earthquakes in 2004 that triggered the Tsunami disaster, people are trying to find out the possible causes for the apparent instability of the earth’s Crust. Many researchers are of the view that the weakening of earth’s vital magnetic shield may be the possible cause of these massive destructions.

Today the earth’s magnetic field is decreasing very rapidly, at a rate that it will last only into the next millennium. If the magnetic field dies, it will also mean the death of the Blue Planet. This decreasing magnetic field was evident from a very surprising source. It’s hard to believe that pottery records the earth’s magnetic field. Clay contains tiny pieces of an Iron based mineral called Magnetite. This magnetite is composed of lots of tiny magnets at the microscopic level. These magnets all point in different directions and fail to create any resultant magnetic field in raw clay. The high temperature of the kiln erases all magnetic regions. But as the pot cools, new magnetic regions are regenerated which align in the direction of the earth’s magnetic field thus making the pot slightly magnetic.

Once cooled, the magnetism gets locked in. The strength of the field depends on the field it has magnetized in. John Shaw from the University of Liverpool examined the pottery from prehistoric to modern times and plotted the results from the ceramics.

He saw gentle changes as we come forward in time over twelve thousand years, a gentle rise and then a rapid fall, as we come towards the present day.

The rate of change is higher over the last three hundred years than it has been for any time in the past five thousand. It’s going from a strong field down to a weak field, and at a very high rate. This change can also be evident from the lava samples of different periods.

Mechanika, 2008

Earth’s Magnetic Field

Global Magnetic Field But it was 50 years ago when a group of scientists examined the magnetic field in older Hawaiian lava samples, they found that the magnetic field inside was pointing south away from the north.

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science & technology

According to Mark Fuller, University of Hawaii, “It was hard for people to accept. They did not like the idea that the field reversed. It took about 50 years to convince people of this. That the Earth’s magnetic field reverses is an extraordinary phenomenon, but this reversal process is quite common. The last reversal was what, 780,000 years ago. Before that, there was one about 200,000, before that, again, actually less than 200, so in a sense we are a bit overdue for a reversal.”

The Cause of Reversals

Earth’s protective magnetic shield

The causes of these reversals are still under doubt. Many scientists believe that reversals are an inherent aspect of the dynamo theory of how the geomagnetic field is generated. In computer simulations, it is observed that magnetic field lines can sometimes become tangled and disorganized through the chaotic motions of liquid metal in the Earth’s core. In some simulations, this leads to an instability in which the magnetic field spontaneously flips over into the opposite orientation. This scenario is supported by observations of the solar magnetic field, which undergoes spontaneous reversals every 7-15 years. The next solar flip is due to occur in 2012.

This may be the reason why the magnetic field is getting weaker these days or may be our planet is getting ready for another reversal. The wiping out of the gigantic life forms like dinosaurs from the face of the earth could be a result of past weakening of magnetic field leading to reversals. If so, what could be the result of today’s magnetic field weakening? The weakening intensity suggests that we will be more exposed to the cosmic radiations from the Sun, this clearly means more deaths from cancer per year. Hundred thousands of people would die from the increased space radiation per year. The radiations could also have serious effects on crops, electronic goods, etc. It maybe that no one of us live to see the next reversal but let’s hope that it would bring with it fun and many great ideas rather than destruction. Gary Glatzmaier (University of California, Santa Cruz) also seems positive when he said, “It’ll be something to be concerned about, but it won’t be a catastrophic event. And certainly by the time it happens, civilization will have figured out how to deal with it”.

“Comets can travel around the sun at about 160000 km/h making them some of the fastest objects in the solar system.

Closer it is to sun fatser it would be. Point at which it is closest to sun is called perihelion and farthest one is called apehelion”

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Mechanika, 2008

science & technology Courtesy: www.googlescholar.wordpress.com

Theory for Everything

by Rohit Koolwal

“Not many people realize that Albert Einstein’s greatest theory was never finished i.e. “Theory for everything”. His crowning achievement would have been The Unified Field theory that would explain all physical phenomena from the birth of universe, to supernovas, to atoms and molecules. A unified field theory allows all of the fundamental forces between elementary particles to be written in terms of a single field. He spent last two decades of his life searching for this theory”

Mechanika, 2008

M

Cosmologists believe that everything began after a huge explosion called The Big Bang. The big bang theory does not tell anything about what banged, why banged and what were the conditions immediately after the bang. Even the laws of physics do not hold good at the time of big bang. Now the string theory has to explain how the world began. But as people worked on it they found five different string theory namely Type I, Type IIA, Type IIB, Heterotic E8 and Heterotic SO32. String Theory has previously displaced the idea of super gravity. The contrasting features of these two theories were the number of dimensions in the universe. The former considered ten dimensions (nine spatial and one time dimension), while the latter considered eleven dimensions (ten spatial and one time dimension).

But with the loss of uniqueness, the string theory was in trouble, so some people started working on the eleventh dimension. Adding one dimension in the string theory made all the five different string theory to be clubbed again into one. These theories are related by transformations that are called Dualities. These dualities link quantities that were also thought to be separate. These five different theories

any theories have been put up claiming to be the Einstein’s missing theory but one idea was the most revolutionary of all. The theory was so provocative that it immediately began to sound like a perfect Theory for Everything.

It was all to do with strings, The String theory. It has been thought that matter was made up of tiny, invisible particles. But now the point of view has changed and the matter is considered to be made up of little strings. The building blocks in string theory are one-dimensional extended objects called strings. According to it, the subatomic particles in nature are nothing more than different resonances of the vibrating superstrings, in the same way that different musical notes emaCourtesy: www.misunderstooduniverse.com nate from the different modes of vibration of a vio- turned out to be different manifestations lin string.

For this to be Ein- of a more fundamental theory, M-Theory. stein’s missing theory, it has to Now, the basic idea of string theory, tiny explain the birth of universe. invisible strings, has changed. When the 21

science & technology physicists look at the computer model of the eleventh dimension, i.e. from the point of view of the eleventh dimension they found that the ‘String’ changed. They stretched and they combined. In the standard string theories, strings are assumed to be the single fundamental constituent of the universe. M-theory adds another fundamental constituent-membranes. The astonishing conclusion was that all the matter in the Universe was connected to one vast structure, which was called a membrane. When Witten named M-theory, he did not specify what the “M” stood for. He says that M stands for “magic”, “mystery”, or “matrix” according to taste. Some suggest M stands for “membrane”, some other says “mother of all theories”, “master theory”, or “missing”. A membrane, or brane, is a multidimensional object, usually called a p-brane, with p referring to the numberof dimensions in which it exists. The value of ‘p’ can range from zero to nine, thus giving branes dimensions from zero (0-brane for point particle) to nine. The eleventh dimension could be of maximum one trillionth of a millimeter. We can observe only three spatial dimensions and one time dimension because the other seven spatial dimensions are “curled up” or “compactified”. The eleventh dimension exists only one trillionth of a millimeter from every point in this three-dimensional world and our membrane universe is floating. Some people suggested that there could be another universe pulsating at the opposite end of the eleventh dimension.

Courtesy: www.hiddenmeanings.com

Another phenomenon which astonished scientist was the weakness of gravity. This force was very weak as compared to other forces such as electromagnetic forces. So they started thinking whether the other dimensions that we can’t see are reducing the strength of gravity, i.e. gravity is leaking from other universe to our’s and on that membrane, it is as strong as other force. Believing this, everything has now began to exactly fall in place and weakness of gravity can be explained but with the idea of Parallel

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Universe. Quantum superposition, a phenomena exhibited by particles, meant that objects can be in more than one place at once, suggested that parallel universes exist. The parallel universe was the perfect explanation of the problems but physicists could find more and more number of parallel universe. This leads to emergence of the idea of infinite number of parallel universe. They believe that some were like our universe, some were completely different with different laws governing natural phenomenon. There could be one universe in which we all were never born, and in some other Napoleon won the Battle of Waterloo and in other, Einstein is still alive and has already found the Theory for Everything.

Still, the beginning of the Big Bang, commonly called as singularity, has to be explained to explain the universe completely. The possible explanation could be that brane collisions produce all of the effects of the early universe and they collide to produce the ‘Big Bang’ effect. There are ripples in the surface of each brane and when they come together they don’t hit at exactly the same time, same place, but in fact they hit at different points and at different times. So when the collision takes place it imparts those ripples into real matter. This could explain the birth of universe and resolve singularity.

The understanding of the multiverse is that there could be an infinite number of universes each with a different law of physics. Big Bangs probably take place all the time. Our Universe coexists with other membranes, other universes which are also in the process of expansion. Our Universe could be just one bubble floating in an ocean of other bubbles. However, some physicists claim that the multiverse theories lack empirical correlation and testability. There is no accepted unified field theory yet, and this remains an open line of research.

REFERENCES • http://www.bbc.co.uk/science/horizon/2001/paralleluni.shtml • http://science.howstuffworks.com • http://www.wikipedia.org

Mechanika, 2008

science & technology

The Automated Guided Vehicles

by V Rohit

“The Automated Guided Vehicle is a mobile robot used in industrial applications to move materials around a manufacturing facility or a warehouse”

Fig. 1: Light-duty assembly AGV

A

utomated Guided Vehicles (AGV’s) have now become quite popular in automated material handling systems, flexible manufacturing systems and even container handling systems. AGV’s help to reduce the total manufacturing cost and increase the efficiency in a manufacturing system.

Timely movement of materials is a critical element to an efficient manufacturing operation. The costs associated with delivering raw materials, moving work in process and removing finished goods must be minimized while also minimizing any product damage that is the result of improper handling.

An AGV system helps streamline operations while also delivering improved safety and tracking the movement of materials. Today, a country like India has surplus human force and thus the cost of human resources is not of much importance. But, pretty soon there will surely be a demand for more labor and that is when the manufacturing industry can look up to these AGVs to help accomplish the tasks at a cheaper cost with greater efficiency.

AGV’s can tow objects behind them in small trailers which they can autonomously hook up to. These trailers can be used to move raw materials into line to get them ready to be manufactured. The AGV can also store objects on a bed. The objects can be placed on a set of motorized treads and then pushed off by reversing them.

The first AGV was brought to market during the second half of the twentieth century. At the time it was simply a tow truck that followed a wire in the floor instead of a rail. Over the years the technology has become more sophisticated and today automated vehicles are mainly Laser navigated e.g. LGV (Laser Guided Vehicle). In an automated process, LGV’s are programmed to communicate with other robots to ensure product is moved smoothly through the warehouse, whether it is being stored for future use or sent directly to shipping areas. Today, the LGV plays an important role in the design of new factories and warehouses, safely moving goods to their rightful destinations.

Mechanika, 2008

Fig.2: Inner Guided Automatic trailer loading vehicle

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science & technology Although, the AGV’s have announced their arrival into the industries the main problem which still remains to be troubling the scientists and researchers is the problem of finding optimal routes for the AGV’s which are inferior to human drivers in terms of sensory and decision making abilities.

The routes for AGV’s are designed in two ways, static routing and dynamic routing. Static routing refers to the scenario wherein the routes are formulated before hand assuming there shall not be any break down of the vehicles.

Dynamic routing refers to the more realistic scenario wherein routes are formulated in real-time even when one of the AGV’s breaks down. Although, till recently research was basically focused on static routing the importance for dynamic routing has been recognized.

Industries like Daimler Chrysler and Honda have been using AGV’s in their units to increase the efficiency of their production.

Automotive Applications HONDA Features Date Installed

2002

Vehicle Type

Side Reach Lift

Number of Vehicles

11

Application Description Transport Stamped Parts Industry Description

Automotive

Guidance Method

Laser

Load Description

3,000 lbs

SGV Host Controls Pick/Drop Type

Windows NT(R) Racks and Baskets

Building Size

30,000 square feet-Phase 1

Fig. 3: Automotive Applications of AGVs in Honda

DaimlerChrysler Features Conveyor Deck SGV

Tugger SGV

Date Installed

December/January 2006

Vehicle Type

Conveyor Deck, Autocart and Tugger

Number of Vehicles

15 each

Guidance Method

Laser

Industry Description

Automotive

Vehicle Capacity

Conveyor - 3,000 lbs Autocart - 1,000 lbs Tugger - 20,000 lbs

Load Description

Racks of components, instrument panels and auto body parts

Autocart SGV

Battery Charging Method Opportunity Throughput

Upto 27 deliveries per hour facility produce 81 vehicle/hr

Facility Location

Belvidere (Rockford)

Fig. 4: Automotive Applications of AGVs in DaimlerChrysler

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science & technology

Conveyor Deck SGV: Operates in the Trim/Chassis Final (TCF) area of the plant and transports racks of engines, shocks, struts, and suspensions from the manual receiving dock conveyors to lineside conveyors. The conveyor deck vehicle picks-up loads from eight receiving dock linear conveyors and delivers them to drop locations at the lineside indexing conveyors.

Autocart SGV: Operates in the Trim/Chassis Final (TCF) area of the plant and transports racks of instrument panels from the automated receiving dock to lineside conveyors, and also returns empty racks.

Dock stripping equipment which consists of a robotic arm loads and unloads powered Over-the-Road Trailers, and places materials directly onto the Autocart vehicle. The Autocart also interfaces with accumulation conveyors at each lineside operator station.

Tugger SGV: Tows/pulls racks of autobody components from the ASRS in the Body-in-White (BIW) area to lineside positions in the Trim/Chassis final (TCF) area. When at the lineside drop position a froklift opeartor unloads full containers from the Tugger trailers and replaces them with empty containers. The Tugger SGV then travels back to the ASRS area to deliver the empty containers, and the process is repeated.

“Owing to the great advances in the fields of artificial intelligence and intelligent manufacturing better routing techniques are being formulated every day, all around the world to make things simpler and more effective”

Benefits • • • • •

Reduced labor costs Improved safety through reduced fork truck traffic Improved production efficency (plant produces 81 Dodge Caliber vehicles/hr) Flexible solution for plants changing production demands Safe reliable delivery of components

REFERENCES • Hsu, W.-J. and Huang, S.-Y., 1994, Route planning of automated guided vehicles. In Proceedings of Intelligent Vehicles, Paris, pp. 479±485.

• Le-Anh, T., De Koster, R., in press. Online dispatching rules for vehicle-based internal transport systems. Technical Report ERS-2004-031-LIS, Erasmus Research Institute of Management (ERIM), Erasmus University Rotterdam, International Journal of Production Research.

• Tuan Le-Anh, M.B.M. De Koster., A review of design and control of automated guided vehicle systems, European Journal of Operational Research 171 (2006) 1–23.

• Samia Maza, Pierre Castagna, A performance-based structural policy for conflict-free routing of bidirectional automated guided vehicles, Computers in Industry 56 (2005) 719–733.

• Jervis B. Webb, Worldwide Material Handling Solutions: http://www.jervisbwebb.com/Categories/AGVs.aspx?cid=3 • FMC Technologies: http://www.fmcsgvs.com • Wikipedia: http://www.wikipedia.org

Mechanika, 2008

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science & technology

Perimeter Security Systems “Crash Rated Active Bollards”

by Prathyusha.M

As passenger safety is of paramount importance to the manufacturer of passenger vehicles, so is the security of the nation to its government. Recent developments in the usage of heavy vehicles by militant outfits to carry out attack has become the main concern of many governments around the world, hence the existence of some kind of barrier to stop vehicles from entering restricted areas was thought of. Bollards are one of the most effective equipments which without being much expensive provide both visibility and high security. A bollard pole with sufficient energy absorbing capability can be used as a simple restraint at dead ends of the road to save lives. These bollards can be deployed quickly and effectively, even in places where it is impossible to excavate for a permanent foundation.

A

bollard is an aesthetic concrete/steel barrier used to protect critical infrastructures as well as define a roadway or path. Bollards are unobtrusive and enhance the site appearance while providing the highest protection needed.

Automatic bollards as the name suggests, are automatic in operation and detect a vehicle by an authorization pre-programmed into the system. The crash rated ones are the most critical and used for perimeter security. Even when the passage is obstructed, if a vehicle tries to intrude, it undergoes a crash with the bollard and completely collapses but the bollard still stays upright and continues to function the same way as it did before the crash.

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Bollards Lined up infront of a museum as a protective measure for the monument

Mechanika, 2008

science & technology

PRINCIPLE OF OPERATION Bollards are designed with an inner steel core coated in a polyurethane casting, whilst the outer casing is constructed from a hard polyurethane compound. In its withdrawn position, the bollards descend hydraulically into the outer casing located below the ground level. A maximum of 4 bollards can be operated from each system. A typical bollard operates from a single phase 240 V supply, rated at 13 amps. The system is controlled by a micro processor based Programmable Logic Controller (PLC) which provides programmability for complex access and traffic control systems. The controllers together with the Hydraulic Powerpack, safety circuits, power supplies and peripheral controls are housed in a road side cabinet.

The basic principle of stoppage of a vehicle is energy absorption. A vehicle moving towards a barricade has a certain kinetic energy, which is the major measure of how much “hitting power” it possesses. Mathematically, kinetic energy is derived from the vehicle velocity and its weight (mass). On impact, some of this energy is converted to heat, sound and permanent deformation of the vehicle. The barricade absorbs the remainder of this energy if the vehicle is to be stopped.

The amount of remaining energy varies depending on several factors, primarily the velocity of the vehicle at the moment of impact. The amount of kinetic energy possessed by a vehicle changes as the square of its velocity. For example, a vehicle moving at 50 mph has 25 times as much kinetic energy than it would at 10 mph.

SPECIFICATIONS Bollard diameter

200 mm

Bollard height

700 mm - 800 mm

Bollard finish options

Stainless steel or galvanized mild steel with a round/octagonal polyurethane sleeve

Polyurethane sleeve

Available in different colors

Optimum bollard riser time

2 seconds

Optimum bollard lower time

2 seconds

Power fail status

Bollard down as standard/Bollard up option available

Power requirements

240v single phase 20amp

Mechanika, 2008

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science & technology

CRASH TEST The finished bollard after being installed has been crash tested with different vehicles and impacts. Alternatively, 3D models can be developed using different Finite Element softwares like ANSYS, Hypermesh, CATIA, NASTRAN and LS-Dyna 970 and the simulation of crash test can be done.

Figures above show the complete stoppage of a vehicle at 75 mph impact by a single bollard and the extent to which the truck is damaged

REFERENCES • “Protective Bollard Design for high impact energy absorption” by Bangalore Krishna-Prasad, Bangalore University, Karnataka” • “Dynamic performance of New Design- Energy Absorbing Bollards” by Automotive Safety Engineering Pty Ltd” • http://www.atgaccess.com • http://www.aptcontrols.co.uk • http://securitysolutions.com Interesting Crash Test Videos can be found on the following websites: • http://www.atgaccess.com/products/impact-tested-products.htm • http://www.southwestautomated.com/crashvids.html

“The whole of science is nothing more than a refinement of everyday thinking” - Albert Einstein

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Mechanika, 2008

off campus

Gourami Business Challenge

He is the lone Shell recruit this year from IITG. For the first time Gourami Business Challenge made its presence in India, and only 10 from all over India were selected to be part of this challenge in Malaysia. He was

by Priyesh Sinha the only one from IITG.

The International Energy Agency (IEA) estimates that energy usage could grow by more than half over the next quarter century and possibly double by 2050. A majority of this growth looks set to come from Asian countries, particularly China and India with their increasing economic growth.

Shell Technology India (STI)

S

hell Technology India, a counterpart of Royal Dutch Shell Group that operates in over 140 countries, started its operations in 2006. It will serve as an entry point for the cutting edge Indian talent to potentially move into the wider group. Thus it is the wonderful opportunity for those individuals who wish to make a career in the energy sector, who want to discover the magnanimous world of oil and gas or work towards the alternative sources of power.

Shell recruits individuals for a variety of job profiles from different engineering disciplines viz. Mechanical, Civil, Chemical, Electrical, and Geology to name a few. Recruitment occurs through internships, campus interviews better known as shell recruitment day (SRD) and Shell Gourami Business Challenge.

Shell defines “Achievement” as “the drive and enthusiasm to set one self and others challenging unambiguous targets; the mental and physical resilience to deliver and the courage & self confidence tackle unfamiliar problems and to go against crowds when necessary”.

“Relationship” is describe as “genuine respect and concerned for people, valuing everyone regardless of culture and status, demonstrating on honesty and integrity in all their actions; creating trust by open and direct communication, persuading others by inspiration; sensitivity and clarity of their arguments, arranging clear means of communication and decision making”.

“Capacity” is termed as “the ability to analyze data quickly and learn fast, basing judgment of fact not sentiment, analyzing outside existing boundaries to identify implications ad learning from others; the creativity to propose innovative solutions and manage uncertainty within complex environment to produce workable solutions”.

During any recruitment procedure shell bases its questions to identify the above characteristics and candidate must demonstrate them during the entire period they are evaluated by shell be it interviews (telephonic or Personal interviews), discussions, presentations or any formal interactions.

“The qualities that shell looks for in employees are condensed as CAR&T attributes i.e. capacity, achievement, relationship and technical proficiency”

Mechanika, 2008

My inference during the entire gourami procedure was that when it came to us, the students from India, shell focused more on CAR attributes while the technical aspect was limited to CV screening and brief relatively simple technical interview, where I was asked questions on a project undertaken, the details of which were submitted before hand.

Gourami in its essence is a five day recruitment program where candidates appearing are evaluated on various criterions through variety of procedures. It is annually held in five regions of the world namely Asia – Pacific, Africa, Middle East, Europe and America. The Gourami business challenge held in Malaysia was the first opportunity

29

off campus when ten students from India took part along with candidates from Singapore, Philippines, China, Malaysia, Indonesia and Australia forming a multi–ethnic group of 47 students with technical and non–technical backgrounds. The selections for Gourami in India was done by telephonic interviews for those candidates whose names were forwarded by respective departments of each IITs in numbers specified. In IIT Guwahati ten students (three each from mechanical & chemical and two each from ECE & civil) were interviewed by shell for selections in Gourami.

Gourami is fantasized as a state that has been ruled by sultans but is becoming liberal over the years and has prepared for development. It has rich oil and gas reserves in various parts. The object of this team of 47 candidates was to prepare a business plan to explore, produce, refine, supply and export oil & gas profitably amongst the stringent laws of Gourami.

To achieve the target the team was divided into five groups with 8–10 members each for exploration, production, refining, power generation and economic analysis. The groups were divided such that it had students for technical, financial, HR considerations, each belonging to a different nationality.

As a member of EP South (Exploration & Production South group) the job of my team was to explore and estimate the oil and gas reserves, make a production plan for a constant supply to the refinery and power group, taking care of the financial aspects for a profitable business.

The planning went forward through discussions within my own team, with adjoining teams, by negotiations with representatives of the state of Gourami over tax rebates, land equity and collaborations by way of discussions with contemporary organizations. Then there were presentations at various stages to the project heads and the project was concluded by a presentation to the shareholders of the shell. Finally there was an interview one half of which was technical as previously explained and the other half was based on my contribution in the project development plan.

In order to do the jobs assigned in Gourami, no prior preparations are required. An intelligent reading of all the material provided by shell aids enough to the purpose. Apart from that a technical understanding of the various data and information, analytical thinking, judicious use of provided information at the right time, effective use of different people in the team and an integral participation in the group activity that lasts for about three days would definitely assure success to an individual. Gourami is not about how well an individual is familiar with his area of specialization (be it technical or non technical) but emphasizes more on how does one plan a project intricacies towards a fine completion.

It is notable that while in Gourami, you are not to compete with your mates, but must prove your worth in the tasks you do. It therefore makes the atmosphere very friendly and by the end of a hectic day, different entertainment events are organized which relieves one from the tensions. It also helps to know the different members of the group, their culture and ways of living. In a small period of five days, we 47 at Gourami were like a family irrespective of global boundaries.

As Indians have always proved their worth abroad, so was in Gourami. For any student from IITG, it is no hard nut to crack. A tinge of intelligence and a smart makeover of one’s personality would assure the best results and would definitely make it an experience of a lifetime. I wish all the very best to future Gouramians!!

“Expecting the world to treat you fairly because you are good is like expecting the bull not to charge because you are a vegetarian” - Dennis Wholey

Every team had a coach to assist details. Alongside there were datasheets and information booklets for each candidate as per his/her background and the job assigned. There was also a library to supplement any information alongside the local area network where effective information transfer took place. For sake of evaluation every group had a ‘floating accessor’ who never interacted but made notes on performance of each candidate.

30

Mechanika, 2008

off campus

Science in the lap of Spirituality

by Aseem Bansal

T

he serene and sparkling abode of Lord Venketeshwara, Tirumala, Tirupati Devasthanam, located in Andhra Pradesh was witness to recondite cogitations of the scientific and spiritual warlords of world. Noble Laureate Prof. Roger Kornberg was an agent and catalyst in the heated debates with students well represented from different universities across the globe like the IITs, IISC, IIMs, AIIMS, NITs, DRDO, ISRO, BEL, Oxford University (UK), Stanford University (USA), University of Illinois (USA), National University of Singapore, etc.

In the war of titans, other big players were the likes of Prof. Yash Pal (Padma Bhushan), Dr. Anita Goel (Founder, Chairman and CEO, Nanobiosym Diagnotics), Kota Harinarayana (Padamshree), Vijay Kumar Saraswat (Padamshree) and many more. More than a thousand students participated in the conference which was held in Mahati auditorium (Tirupati). And what’s more satisfying is the fact that main organizer was our very own S. C Mishra sir.

Day 1 of conference started with an exhilarating speech by Sri Sri Ravi Shankar which was followed by various talks, exhibitions, paper and poster presentations on topics like “The synthesis of science and spirituality”, “Parallels between spirituality and quantum theory”, “Ultimate reality: Science and Spiritual paradigms”, “Machine, mind and consciousness”, “Unfoldment of collective consciousness in Indian Spiritual traditions”, “Structure of consciousness”, “Consciousness in relation to Bioelectric Neural Circuitry” etc.

There was also a panel discussion on ‘Science, Ethics and spirituality: a need for a balanced approach’ in which the view point that ethics (dharma) should be at the core of all scientific progress was churned and there was an attempt to obtain an ideal roadmap for future progress.

Next day we had to wake up at 2 am because we had to leave for Tirupati Balaji Darshan at 3 am. The Darshan was also a part of the conference. I was very exited. The buses started exactly at 3 am and went uphill to Tirumala Hills, the home of Sri Balaji Maharaj. Amidst tight security and checking, we finally had the divine darshan of Balaji, an experience which is impossible to limit in words here. After collecting the famous Laddu Prasadam, we returned to the conference where another day of inestimable insights into the absolute reality awaited us.

The day proceeded with orations on subjects like “Scientific exploration and explanation of meditation”, “The nature of time and it’s references in various scriptures”, “Understanding molecular evolution by studying DNA in light of quantum mechanics”, “Mathematization of nature”, “Time dimension: Exploration from science, philosophy and spirituality, Synthesis of Vedic and Modern cosmology”, “Mathematical Techniques for study of EEG data recording during meditation”, “New frontiers in biology and implications for science and spirituality, “The knowable nature of scientific truth” etc. The panel discussion was on the role of spirituality to imbibe values in education.

It was followed by an interactive session with all the speakers including the Nobel Laureate Prof.

Kornberg and Prof. Yash Pal. Finally, the conference concluded with a splendid performance by artists depicting the glories of Lord Sri Venkateshwara and a magnificent drum show, martial arts and rasa–dance by a Manipuri cultural arts troupe.

“A little inaccuracy sometimes saves a ton of explanation” - H. H. Munro (Saki)

Mechanika, 2008

31

survey

Survey Freshers 1 7HICH GAMES DO YOU PREFER TO PLAY

%NTREPRENEUR

1 7HAT DO YOU WANT TO BECOME IN LIFE

/UTDOOR

2ESEARCHER

#OMPUTER

#IVIL 3ERVANT 0ROFESSOR

)NDOOR

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&AMILY

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32

%INSTEIN

$HIRUBHAI !MBANI

"ILL 'ATES

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6IVEKANAND

Mechanika, 2008

survey

Survey Sophomores

1 7HICH GAMES DO YOU PREFER TO PLAY

1 7HICH IS YOUR FAVOURITE COURSE 3OLID -ECHANICS

/UTDOOR #OMPUTER

-ATERIAL 3CIENCE

)NDOOR

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&LUID -ECHANICS

1 7HICH IS YOUR FAVOURITE EVENT IN ))4'

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Mechanika, 2008

30/243

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33

survey

Survey 3rd Year 1 7HICH GAMES DO YOU PREFER TO PLAY

1 7HAT DO YOU DO BESIDE STUDIES

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34

3OLID -ECHANICS

-ATERIAL -ANUFACTURING 3CIENCE 4ECHNOLOGY

Mechanika, 2008

survey

Survey Final Year 1 7HICH GAMES DO YOU PREFER TO PLAY

#3 3/& 1UAKE 6OLLEY

/UTDOOR

&OOTY

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4ENNIS

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44

#RICKET /THERS

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4HERMODYNAMICS

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Mechanika, 2008

3EMESTER

6OTES

3EMESTER

6OTES

3EMESTER

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3EMESTER

6OTES

3EMESTER

6OTES

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&LUID -ECHANICS 35

placements

Placement Report-Session of 2007-2008* Total Number of Registered Students: 46 Total Number of Students Placed: 44 Total Number of job offers: 51 Average salary: 6.2 Lacs Highest salary: 30.12 Lacs Below is the list of companies which visited the institute during the placement session 2007-2008 and considered Mechanical Engineering students. These companies have operations ranging from core mechanical areas to the ďŹ nancial sector.

Core Companies National Thermal Power Corporation (NTPC) TCE Larsen and Toubro Indian Oil Corporation Limited Defense Research and Development Organization Engineers India Limited Fluent Godrej Mahindra & Mahindra John Deere Shell **

ITC RIL NMSEZ Bharat Petroleum Corporation Limited Reliance Industries Limited Coal India Limited Hindustan Aeronautics Limited Schlumberger Ashok Leyland Cummins Tata Motors BILT

Non-Core Companies Evalueserve Tata Consultancy Services Patni PriceWaterhouse Coopers DE Shaw Mu Sigma Absolute Data

*Till 15th March,2008 **Recruitment through Internship

36

Quest Infosys Headstrong Fair Issac Irunway Global Logic Bentley Systems by Kiran Prakash Placement Secretary Department of Mechanical Engineering

Mechanika, 2008

placements

GEAR UP FOR INTERVIEWS

by Final Year students

01

on your weaknesses?

02 Tell us something about

Have you ever done a project which had an industrial exposure?

Tell us something about yourself. your background, your parents, and your siblings.

03 Why we should offer you the job?

04

What are your future

plans?

05

Where do you see yourself five/ten years from now?

16 17

Why don’t you go for MS, PhD or MBA?

18

How will working in our company fit in your future plans?

19

Name one unique activity which you have performed which differentiates you from your peers.

06 Why do you want to join 20 our firm?

Would you have any problem working in an isolated area?

07 How would you fit in our 21 organization?

Do you have any working location preference?

08

What would happen to your core area, your specialization?

09

Don’t you think the package we are offering is low?

10

What are your extracurricular activities?

11

A question related to current affairs.

12

Have you ever been in a situation where you had to take a decision all by yourself?

13

Have you ever led a

team?

14 What are your strengths, your weaknesses?

15

How are you working

Mechanika, 2008

30

Describe three words.

yourself

in

31 I will give you this much amount of money if you jump from 3rd floor. What will you do? If no….Ok I am increasing the amount, now will you jump? If no, will you jump from 1st floor…. and so on.

32

You hold this position during your stay in IITG. Now if some students told you that this IIT system is corrupt (or something else) and we all are going for strike and ask for your help. What will be your response to this situation?

33

22

How you will define a manager?

23

Tell me something about the Sensex. How it works?

How many companies are listed in it?

How would you feel if we place you in any remote area and you see your friends in US or Europe?

Why did you choose your branch?

24

Is it you who decided to have this branch or your parents forced you?

25 Why IIT Guwahati?

26 Do you regret the decision of joining IITG?

27

What would have been your first choice?

28 What are your expectations from our company?

29

Why would you prefer us over your previous recruiters?

34

35 Do you want to ask any question from us?

36 Have you contacted any of your seniors in our company? If yes, what did you ask from him?

37

Did you attend our PPT (Pre Placement Talk). If no, why?

38

What do yo think, IIT brand name works in companies like us where students from other local and NIT colleges work together with students from IIT?

37

research

Two-phase flow instabilities in flow boiling in microchannels Karthik C, Bikramjit Bhatia B.Tech. Final Year (2004-2008 Batch), Department of Mechanical Engineering, Indian Institute of Technology Guwahati

Abstract A nonlinear lumped parameter dynamic model for two-phase microchannel flow that takes microfluidic surface effects into consideration is developed.

A suitable friction factor is de-fined for this flowunder the assumptions of the homogene-ous equilibrium mixture model; a quality weighted average slip length is defined as the slip length of the homogeneous mixture. One-dimensional unsteady mass, momentum and energy conservation equations are then set up for flow in a heated microchannel. With certain assumptions on the spatial variation of the flow properties, these equations are reduced to a system of differential-algebraic equations that can be solved for the time varying outlet mass flux, quality and pres-sure.

Introduction Miniaturization has recently become the key word in many advanced technologies as well as in traditional industries. Compact and micro heat exchangers, micro heat pipes, micro-fabricated fluidic systems and microelectronic devices are being progressively employed in commercial sectors.

Along with single-phase, numerous two-phase (evaporation) cooling applications have also been identified. The phase change process in a microchannel enhances the heat transfer in cool-ing systems of electronic devices, thus allowing the device to function at high power densities.

So far, these two-phase cooling applications are being implemented primarily with the help of extensive testing. Thus thermal design methods for heat transfer and pressure drops are required to predict, optimize and analyze microscale twophase flow systems. Instabilities in small channels have been observed and interpreted using the classical theories developed for large hydraulic diameter channels [1-2].

A two-phase flow system is considered stable when for any applied disturbance, the new operating conditions tend to the initial one. Twophase flow instabilities are undesirable for several reasons- sustained flow oscillations may cause forced mechanical vibration of components or control prob-lems, and affect the local heat transfer

38

characteristics and induce boiling crisis.

This study involves one-dimensional modeling of flow boiling in microchannel flow through a channel. The contin-uum hypothesis is considered to hold, and the effects of the microchannel dimensions on the flow behaviour are taken into account via a modified slip length parameter. A Homo-geneous Equilibrium Mixture (HEM) model is proposed for two-phase microchannel flow. The objective is to study im-portant dynamic characteristics of the flow. Thus, despite the simplified nature of the model, important qualitative features of two-phase flow instabilities in microchannels are expected to be revealed.

Theoretical basis Gas solid interactions play a major role in the properties of fluid flow in microchannels. Near a wall, the local Knudsen number Kn plays a vital role in characterizing the nature of energy and momentum transfer between the wall and the molecules.

The change in tangential momentum of a gas molecule during a collision with a surface is ( ), with and being the momentum before incidence and after reflection. If is the momentum of the molecule corresponding to the velocity of the wall, the ratio is called the momentum accommodation coefficient σv , and is a property of the gas surface pair.

Further considerations from the kinetic theory of gases [3] reveal that the slip at the wall, defined as the differ-ence between the gas velocity tangential to a surface and the velocity of the surface can be obtained in terms of the mo-mentum accommodation coefficient to be (1)

where λ is the mean free path, and y is the direction normal to the surface. For liquids, a sound theoretical foundation that predicts slip at solid surfaces does not exist, and the surface interaction modelling is primarily phenomenological. Thomp-son and Trojan [4] found in a Couette flow arrangement that the slip-flow boundary condition for liquids can be stated in terms of a slip length Ls as Mechanika, 2008

research

(7) (2)

in the regime where , the continuum hypothesis may be assumed to hold [3]. In the modelling carried out in the following section, the continuum hypothesis is used in con-junction with Eqs. (1) and (2) to account for microfluidic ef-fects.

where Um is the average (homogeneous) velocity of the mix-ture. In addition (and in analogy to Eqs. (5) and (6)), we have defined (8) This formulation is expected to yield a conservative estimate for the two-phase friction factor.

The equations of the system dynamics are then ob-tained from control volume mass and energy balances of thesingle and two-phase flow regions in the microchannel. With the assumption of linear spatial variation of quality with length in the boiling region, the result is a non-linear differen-tial-algebraic system of equations that can be solved to yield the time evolution of the system: (9)

Figure 1: Schematic of the domain the model is applied to

(10)

Modeling details

(11)

The simplest and most important component of a micro-scaled device used, for instance, in cooling applications, con-sists of a heated microchannel where boiling occurs. The do-main of study is shown in Figure 1.

The assumption of steady micro-Poiseuille gas flow yields, for the Darcy friction factor, (3)

Where, η is a function of the momentum accommodation term that accounts for the gas surface interaction, and Kn is the Knudsen number of the gas flow.

A corresponding relation for liquids exists in terms of the empirically defined slip length Ls. Weighing the two slip length terms based on the quality of the flow yields a slip length for the assumed homogeneous mixture K. The two-phase friction factor fTP is then given by (4)

Here, as per the conventional HEM model,

(12) Here, Gi and Ge are inlet and exit mass fluxes, is the average volume fraction in the channel, χe is the exit mass fraction, Zbb is the boiling boundary length, and A and q are the flow cross-sectional area and the heat addition per unit length of the channel. hfg and ρfg are defined as hg - hf and ρf - ρg respectively. In addition, momentum balance for the control volume flow gives:

(13)

which predicts the pressure drop across the channel as a function of the solution to Eqs. (9)-(12) and the above defined modified friction factor, Eq. (4). The integral of mass flux over the length of the channel has been simplified by ap-proximating it with the product of the exit mass flux from each region and the length of the region.

REFERENCES

(McAdams relation)

(5)

(6)

Mechanika, 2008

• Tadrist, L., “Review on two-phase flow instabilities in narrow spaces.”

Int. J. of Heat and Fluid Flow 28 (2007) 54-62.

• Bergles A.E., Lienhard V.J.H., Griffith P., 2003. “Boiling and evaporation in small diameter channels” Heat Transfer Eng. 24 (1), 18-40.

• Liou W, Fang Y, 2006. Microfluid Mechanics- Principles And Modeling, McGraw-Hill, Nanoscience and Technology Series, ISBN 0-07-144322-2.

• Thompson, P.A. and Trojan, S.M., A general boundary condition for liquid flow at solid surfaces, Phys. Rev. Lett., Vol63, p.766, 1997.

39

research

FINITE ELEMENT ANALYSIS OF MIXED MODE FATIGUE CRACK GROWTH PROBLEMS Neela Praveen Kumar M.Tech. Final Year (2006-2008), Department of Mechanical Engineering, IIT Guwahati

A new incremental formulation for predicting the path of a two-dimensional fatigue cracks is presented and implemented. First, the fatigue crack path and its stress intensity factor are calculated in specialized finiteelement software, using small crack increments. The real extension path of cracks is simulated by a linear incremental crack extension, based on maximum principal stress criterion. At each crack propagation step, the crack extension is conveniently modeled and mesh is redefined using finite element software. Stress intensity factors are noted from the software and the orientation of the incremental crack is calculated based on maximum principle stress criterion, which states that crack propagation takes places in a direction perpendicular to that of the applied loads. Number of load cycles required for each incremental crack step and fatigue life analysis is carried out with Pari’s law. Several numerical examples are solved using this method, and the actual propagation taking place in different stages of crack growth is shown below.

The crack propagation taking place in a edge crack from initial length to final length in different stages is shown in sequence.

40

Mechanika, 2008

research

The crack propagation taking place in inclined center crack at different stages is shown.

The fatigue life is determined by using pari’s law, and is given by,

The number of loading cycles required for a particular amount of crack growth in successive steps is given by, ,

h=0, 1 .....n

The present investigation is also aimed to look at the different techniques that are available for determining the fatigue crack path under cyclic loading for mixed mode problems. As a first step, various numerical methods that are available for determining the fatigue crack growth path of a mixed mode problems have been studied. It has been found that incremental method is the best method available for solving mixed mode crack problems at present. Apart from this a numerical study is also conducted in understanding the concepts involved in understanding the incremental formulation.

“A university is what a college becomes when the faculty loses interest in students”

- John Ciardi

Mechanika, 2008

41

research

Vibration Problems of the Primary Limestone Crusher Unit, a Case Study R. Tiwari, S. K. Dwivedy and D.J. Bordoloi Mechanical Engineering Department, Indian Institute of Technology Guwahati

Abstract In this work attempt has been made to find the root cause failure of the spline shaft in a limestone crusher unit based on vibration measurements. Vibration spectrums were taken by an accelerometer using a portable vibrometer and a digital storage oscilloscope at several critical places of the crusher unit and they have been analysed to find the root cause failure. Recommendations are given to avoid such kind of failure in future.

Background The primary lime stone crusher unit of very a large cement factory has been reported here which had the following problems. Originally the crusher unit was operating for crushing of 350 metric tons of stones per hour (MTH). A 224 kW motor operating at 1493 rpm was used to drive the four-stage gearbox (with a gear ratio of 45:1), which was connected, to the crusher unit. To enhance the productivity, later it was decided to increase the capacity to 650 MTH for which a motor with power 300 kW operating at the same speed of 1493 rpm was used.

Feeder unit

Crusher unit Motor and fluid coupling assembly

4-stage gear box

Sizer Crushed limestone

Cantilevered frame

Support structure Fig.1 Schematic diagram of the crusher unit

The first and second stage of the gearbox was also changed to have a speed reduction of 33.5:1. The severe vibration problem started after changing the motor unit. This results in severe vibration problem even at low feed of operation and frequent failure of the spline shaft which was used to couple the sizer of the crusher with the gear box (Fig. 1). The gearbox is connected to the motor through a fluid coupling.

42

Mechanika, 2008

research

Onsite Observations Following observations are made during onsite visit of the plant: • A relatively very heavy motor and gearbox unit (Figure 2(a)) were on the overhang configuration attached to the main crusher unit.

• On close observation of the failure of the shaft that took place (Figure 2(b)), it showed that it failed perfectly in the transverse plane (a plane perpendicular to the shaft rotational axis). Moreover, the close observation of gears on the last stage of the gear train reveals that they had no severe damage; even the gear mounted on the crusher side had no damage.

The vibration spectrums (Figure 3) were taken at different points on the machine by using an accelerometer and FFT analyzer to study the root cause of failure.

Root Cause Analysis and Discussions Possible reason of failures: (i) Severe misalignment between the splined shaft from the gearbox to the input shaft of the crusher unit, (ii) Development of misalignment due to excessive clearance or loosened at one of the bearing of the crusher during crushing. (iii) One of the bending natural frequencies of the overhang motor-gearbox unit might be close to the excitation frequencies of the impulsive forces coming from the breaking of stones, (iv) resonance of the structure due to coinciding of the excitation frequency with the natural frequency of the structure.

Table 1 Torque transmitted in the old and new motor-gearbox units With gear ratio 45:1 (old design)

With gear ratio 33.5:1 (new design)

Motor speed

1493 rpm

Motor speed

1493 rpm

RPM of the crusher roller

33.17

RPM of the crusher roller

44.56

Power of motor

224 kW

Power of the motor

300kW

So torque transmitted

64.487 kN-m

Torque transmitted

64.29 kN-m

It may be observed from the calculations shown in Table 1 that the torque transmitted to the rotor of the crusher unit from the motor and gearbox assembly remain constants even after changing the motor and gearbox assembly. Hence it suggests that the failure is not due to the shear (i.e. the heavy torque transmitted through the shaft); instead it was due to the bending of the splined shaft. The overhang configuration infuriated the bending stresses in the splined shaft, especially during the crushing of the stone when large impulsive forces come from the crusher rollers to the motor-gearbox unit to cause the overhang portion to vibrate in the transverse plane in bending.

Figure 2. (a) Overhang motor-gearbox assembly, (b) the gear train Mechanika, 2008

43

research

Figure 2. (c) the cracked spline shaft, (d) failure of the additional support of the box type structure At no load conditions the order of magnitudes of vibration at the motor end was 2-4 mm/s, and the whole crusher unit runs very smoothly (at 44.45 rpm) without any major oscillations of the structure. However, observation of large vibrations (of the order of 7 to 21 mm/s at the part load to the full load, respectively, on the crusher rollers) measured at motor end during the crushing of stones, suggested that the crusher unit was getting the misalignment or the resonance conditions. The misalignment can come either due to improper mounting or large clearance in bearings. The main excitation towards this resonance was the impulsive force produced during the breakage of bigger stones. These impulsive forces contain several frequency components and it is possible to have resonance, if one of the system natural frequencies falls within the excitation frequency range.

(a)

(b)

22 Hz Natural Freq

Amplitude --->

2 Hz

Amplitude --->

38 Hz 70 Hz Gear Mesh Frequency

Frequency (0-200 Hz)

2 Hz 64 Hz

Frequency (0-200 Hz)

(c)

(d)

Amplitude --->

Amplitude --->

2 Hz

Frequency (0-200 Hz)

42 Hz 58 Hz

124 Hz

Frequency (0-200 Hz)

Figure 3: Signal spectrum from (a) the gearbox housing in the vertical direction of motion (bending)(1020mm/s) (b) gearbox housing in the horizontal direction of motion (bending) (6-13 mm/s), (c) the gearbox housing in the horizontal direction of motion (axial) (10-17 mm/s), (d) crusher housing in the vertical direction of motion (vibrations of 6-20 mm/s with feed).

44

Mechanika, 2008

research Since gears were transmitting large torques, they generate various forces of different frequencies to the gear housing.

Excitation frequency from motor speed

1493/60 = 24.88 Hz

Excitation frequency from the I stage of the geartrain

24.88 x 31 = 771.4 Hz

Excitation frequency from the II stage of the geartrain

24.88 x (31/66) x 21 = 245.4 Hz

Excitation frequency from the III stage of the geartrain

11.69 x (21/87) x 25 = 70.5 Hz

There are rotational frequencies from shaft rotations, i.e., 24.88 Hz (I gearshaft/motor; 24.88 Hz is equal to 1493 rpm), 11.69 Hz (II gearshaft), 2.82 Hz (III gearshaft) and 0.74 Hz (IV gearshaft/crusher-roller; 0.74 Hz is equal to 44.4 rpm).

Figures 3 shows the vibration spectrum of gearbox and crusher unit and vibration signals measured in various directions. It clearly shows two predominant frequency components (i.e., one at 2 Hz and another at 20 Hz). Apart from these, there are several but not that much predominate peaks, which are related to gear meshing frequencies with sidebands, and their harmonics throughout the frequency spectrum (i.e., between 0-200Hz). The 2 Hz frequency is quite predominant, and it is 2 x of gearshaft IV or the spline shaft, which is the case when there is severe misalignment of the shaft. This particular peak (or their higher harmonics) persisted in almost all the signals captured (Figs. 2(a-d)). It suggests that it is always present irrespective of the amount of feed to the crusher. The misalignment of the shaft might be due to improper assembly or due to severe vibration of gearbox assembly with respect to the crusher unit due to one of the several resonance conditions. The frequency 20 Hz is not seen in other plots suggesting that it is one of the natural frequencies of the system, which is getting excited occasionally, whenever frequency of excitation emitting from stone crushing is getting tuned with it. Hence, it is not of major concern. The large displacement of the structure as observed during our visit to the site, also suggest that mostly the lower frequency components were getting excited since in general the high frequency of oscillations have small amplitude of vibration.

Recommendations (i) Ensuring the proper alignment of the spline shaft, and proper mounting of the bearings of rollers of the crusher unit. (ii) Support the overhang motor by means of beams on the box type main structure on which whole crusher unit has been mounted. Better options would be to provide dampers beneath the motor and gearbox units similar to as shown in Fig. 4(a), which are very effective especially when system is near resonance conditions. (iii) Strengthen the support of the main box type structure by providing additional crossed beam from various joints to the foundation (i.e. inverted V shape beams at main columns to prevent their transverse vibrations as shown in Fig. 4(b)).

Figure 4 (a) Isolation systems (b) additional stiffening members to the box type struc-

Conclusions

In the present case study, it is shown that here viAdditional bration signals from maSupport chinery can be used to detect an incipient fault in the speciďŹ ed shaft due to misalignment. Indeed it is possible to detect such fault well before it causes Isolation system consists of an inertial base and a series of spring severe damage to the maisolators (inset) which reduce the transmission of the vibration and shock chine elements. The adto the structure. vantage of vibration based detection technique is that, it can be used during normal operation of the machine without disturbing the production schedule. Now days such condition monitoring of machinery is becoming very popular and reliable especially when it is used as on-line.

Mechanika, 2008

45

research

M.Tech. Projects Allotted for 2007-08 session 1

A. Ravi Kumar

Localisation of a Crack in Rotating Shafts

2

Ambati Apparao

Tool path generation for heterogeneous objects

3

Amit Kumar Rawal

Damage tolerance analysis of composite material

4

Anil Kumar

FEM modeling and analysis of Smart FGM Composite plate and shells

5

Bala Krishna Chimmineni

Two-phase flow instabilities in minichannels

6

D.S. Vamsi Kiran

Numerical study of heat transfer and hydrodynamics in circular tube heat exchanger.

7

Deepak Kumar Verma

Computation of Flow and Heat Transfer for Supercritical Water using FLUENT

8

Dipendra Mishra

Application of a micromechanical piezoelectric material model in a hybrid solid shell element

9

G. Krishnaiah

Numerical Computation of One-Dimensional Unsteady Two-Phase Flow

10

G.R. Santosh Kumar

Numerical Studies of Laser Forming

11

Harjeet Kumar Banjare

Stability Analysis of Porous Bearing

12

Kake Siva Sankar Reddy

Fatigue and wear analysis of artifical hip joint using FEM

13

Kamble Ajinath Hanmant

Finite element formulation of Micro-rolling process using strain gradient plasticity theory

14

Kaushik B

Finite Element Determination of Gage Locations in the Strain Gage Techniques

15

Kinthada Veerababu

Application of Artificial Neural Network technique in predicting the tensile and deep drawing behavior of Tailor Welded Blanks

16

Kishore Kumar Boni

Study of Dynamics of Liquid Sloshing in Tanks

17

Kovalam Sunil Kumar

Optimum Design and FEM Analysis of Rolling Element Bearings

18

Lakavath Praveen Kumar

Processing, Mechanical Properties, Deformation Behavior and Structure Property Correlation of Micro Alloyed Al-Cu Alloys

19

Leeju C J

Measurement of Pressure Composition Isotherm Charcteristics of various metal hydradides

20

Manoj Kumar Sinha

Modelling of Multi-hole Extrusion Process

21

Meeravali Shaik

Solving conduction-radiation problems using the LBM and FVM and their parallelization

22

Mulpuri Ashok Kumar

Study of Instabilities in Super Critical water Reactor.

23

Chakradhar Neppalli

Cartesian mesh generation

24

NEELA PRAVEEN KUMAR

Finite element analysis of mixed mode fatigue crack growth problems

25

P. Manikandan

Development of Shell Finite Element for Analysis of Smart Structure

26

P. Venkateswarachoudari

Optimal synthesis of mechanisms for precise path generation

27

Pandaba Patro

Three dimensional modelling and numerical simulation of a circular pin fin heat exchanger

28

Patil Tushar Ashok

Development and simulation of an 2D unsteady, explicit, compressible code for unstructured meshes

29

Pavitran Yanamadala

Heat, mass and moisture characteristics of a fluidized bed dryer

30

Praveen Kumar G

Analysis of Conduction-Radiation Heat Transfer Problems on Unstructured meshes using the FVM & LBM

31

Rohit B. Ramtekkar

Performance of Axial Flow Fans Using FRP Composites Aerofoils

32

Sandeep S

Three Dimensional Numerical Simulation of Flow in Cross-Corrugated Plate Channels

46

Mechanika, 2008

research

33

Santosh Basa

Development of a 2D cell-vortex (median dual) inviscid compressible finite volume flow solver on unstructured meshes

34

Sepena Venkata Ramana

Studies on coupled heat and mass transfer in metal hydride reaction beds

35

Srinivas Madduri

Parametric vibration analysis of sandwich beam

36

Srinivasulu M

Dynamic Analysis of Composite Flexible Robotic Manipulator using FEM

37

Sunil Balwant Deshpande

Vibration Characteristics of Thermoplastic Composites

38

T.B. Pavan Kumar

Analysis of Non-Fourier conduction-radiation heat transfer with constant and pulsed heat source using the LBM & FVM

39

Thammaneni Sreedhar Reddy

Numerical study on couple heat and mass transfer analysis in metal hydride based hydrogen storage devices by using CFD Tool FLUENT

40

TIRUPATHI AMGOTHU

Computational Investigation Of Turbulent Round Jet In Co-flowing Ambient

41

Venkatarama Prasad N

Relative Performance Evaluation of FVM & LBM for Compressible Fluid Flow Problems

42

W Ravi Kumar

Application of Active Magnetic Bearings in Rotor systems

Feelings… (a poor caged bird has its say in these lines) I look around feel the iron bars surround in this captivity I have lost my identity.....

I fail to realise the world outside as I lay inside with a sobbing heart.... the pain pricks me my dreams tease me this haunts my mind every day and night

my persistence, for my existence Will melt the iron down for sure....

days have past but not so fast this daunting task has killed my ask.

I flattered my wings And was ready with my things Waiting for what I wished…..

days have past my struggle did last…… and that one day it was time for my say up did I fly into the lit up sky.. as my feelings soared up high..

It was then when I realized that I was lying off my cot on the cold floor... my heart cries out with pain I ask myself if this wait is in vain I decide by myself as I cry out for help to use the fire in my soul and melt the iron in whole

Mechanika, 2008

by C. Anand Vijay Kartha

47

yearbook

Final year Students Class of 2008 A Vijay Anand

Aditya Taneja

Email Id: knightvijay@gmail.com

Email Id: adityataneja86@gmail.com

Phone No: +91-891-2782663

Phone No: +91-11-29228888

Future Plans: “Going to join Infosys”

Future Plans: “Join NTPC Ltd.”

BTP: “Finite Element Analysis of Hip

BTP: “Modeling and Analysis of Biogas

prosthesis”

digester”

Message: “Dont waste any time since this is the most precious moment in your life”

Alok Verma Email Id: alok.vrm@gmail.com Phone No: +91-11-22452218

Message: “Have fun in life, no matter what” !! :))

Antriksh Singh Email Id: a_free_radical@yahoo.com, psychedelic.shock@gmail.com

Future Plans: “I’ll join NTPC”

Phone No: +91-9971232393, +9111-26106422, +91-9810764291

BTP: “Experimental study and analysis of Heat Pipe”

Future Plans: “Will join RIL as Management Trainee” BTP: “Design & fabrication of active magnetic bearing to control rotor vibrations”

Message: “Work on communication skills, most importantly

Message: “Smell your guts and follow it”

have fun make full use of 4 years”

Anup Raj Email Id: anupraj001@yahoo.co.in Phone No: +91-522-2456434 Future Plans: “Job in Coal India Ltd” BTP: “Finite element analysis of 2-D and 3-D crack problem using Ansys”

Message: “Decide your goal as early as possible. This will give you time for organizing and implementing your plan.

Enjoy IIT life…”

Bed Prakash Gupta

Aseem Bansal Email Id: meetaseem@gmail.com Phone No: +91-164-2213064 Future Plans: Godrej saralee/NTPC BTP: “Internet Based Manufacturing”

Message: “Dont waste ur time in useless course books, but have a passion 4 learning, be it anything, coz it’s the only thing that matters”

Bikramjit Bhatia

Email Id: bedprakashiitg04@gmail.

Email Id: bikram.bhatia@gmail.com

com

Phone No: +91-11-41002419

Phone No: +91-9937080311

Future Plans: “M.S. in USA”

Future Plans: “Beawar (Rajasthan),

BTP: “Two-phase flow instabilities in

Shree Cement Power Plant”

Microchannels”

BTP: “Design & fabrication of cooling tower and its performance improvement by using porous media”

Message: “Labour never goes in vain”

48

Message: “IITG is a treasure island, draw out as much wealth as you can”

Mechanika, 2008

yearbook

B Varun

Bodla Karthik Kumar Email Id: karthikbodla@gmail.com

Email Id: varun.iitg@gmail.com

Phone No: +91-40-24556035

Phone No: +91-8744-243181

Future Plans: “Looking forward to

Future Plans: “Reliance Petro-

pursue higher studies (MS/PhD) in US”

chemicals”

BTP: “Control of Flexible Robotic Manipulator“

BTP: “Development of a cell centered finite volume code for structured meshes and its application to nozzle flows” Message: “Its these 4 years which will shape your future, so live IITG life to its fullest but do not neglect your acads and other stuff. One more thing make as many frns as you can, as frns made herewill, remain frns for your entire life”

Message: “See to it that acadamics is also a part of ur life” ”

CH Vamsi Krishna

KRS Chaitanya

Email Id: cvkreddy@gmail.com

Email Id: chaitanya.krs@gmail.com

Phone No: +91-8742-228258

Phone No: +91-402-4140530

Future Plans: “Job (EIL) or MS( Ohio

Future Plans: “I am yet to find what

State Univ.)”

interests me till then I’ll go with the flow...MS/Job whatever....”

BTP: “Study of Micro Fluid Flows”

BTP: “Strategic Confinement of evaporating Sessile Drop Using Micro spheres for Controlled Nanosphere Assembly for Regenerative Applications and Lab on Chip Techniques” Message: “First of all Know your interests (MS, Job, CAT.....), then start working towards that”

Message: “Please remember that you are here because you want to study, not because you have to study”

G Sarvesh

Gaurav Kumar

Email Id: sarvesh.iitg@gmail.com

Email Id: gaurav_iitg2004@yahoo.

Phone No: +91-8742-226257

com

Future Plans: “Will join Infosys”

Phone No: +91-11-27882618

BTP: “Study of Micro Fluid Flows”

Future Plans: “Join NTPC” BTP: “Internet based Manufacturing”

Message: “Decide your career goals as early as possible and start working towards them sincerely. As they say, try hard to get what you love or you will be forced to love what you get”

Kamal Kant Maurya

Kanad Shaurya

Email Id: maurya221184@gmail.com maurya221184@yahoo.co.in

Email Id: shaurya.iitg@gmail.com

Phone No: +91-120-2320405

Future Plans: “Joining IOCL”

Future Plans: “NTPC”

BTP: “Design & fabrication of cooling

BTP: “Numerical simulation of slosh-

tower and its performance improvement by using porous media”

Phone No: +91-9934017483

ing effect”

Message: “bas mitro aish karo n try to see every aspect of life, enjoy every moment good or bad with same potential, kuch bano ya na bano but atleast try to be a good person”

Mechanika, 2008

Message: “Man dont stop until you fulfill all your promises and dreams”

49

yearbook

Karthik C

Kiran Prakash

Email Id: karthikchikmagalur@gmail. com

Email Id: kiranprakashone@gmail com, kiran_prakash1@yahoo.com

Phone No: +91-80-25717174

Phone No: +91-288-2326908

Future Plans: “Going Home”

Future Plans: “RIL or BPCL”

BTP: “Two-phase flow instabilities in

BTP: “Experimental Investigation of

Microchannels”

mixed mode fracture mechanics”

Message: “Quit complaining and get to work, you have more time than you can possibly realize”

Message: “Stay Foolish and Stay Hungry”

Kshitij Maheshwari

Kunal Kumar

Email Id: maheshwari.kshitij@yahoo.

Email Id: Kunal7iitg@gmail.com

com

Phone No: +91-6250-282858

Phone No: +91-1232-242927 Future Plans: “Joining Godrej Godrej Sara-lee division”

Future Plans: “Joining RIL” BTP: “Modeling and Analysis of Biogas digester”

BTP: “Computer Aided Assembly Process Planning”

Message: “Just follow your heart and instincts, Don’t have any regrets in life. Wish you good luck in whatever you do in your life”

M Nelson

Message: “Preserve your potential and enthusiasm that you had during JEE, and don’t lose that effectiveness. Do not forget why you are here, and do not fear the challenges lying ahead”

Mayank Singh

Email Id: mnelson1986@gmail.com

Email Id: monkinferarri@gmail.com

Phone No: +91-9443911059

Phone No: +91-512-2420233

Future Plans: “Will join Global Analytics in Chennai”

Future Plans: “Join Coal India ltd”

BTP: “Control of Flexible Robotic Ma-

ing effect”

BTP: “Numerical simulation of slosh-

nipulator”

Message: “Play hard, Work hard”

N Bharath Reddy Email Id: nukala.bharathreddy@gmail .com

Phone No: +91-40-27151943 Future Plans: “Evalueserve,Gurgaon” BTP: “Investigations of Metal hydride

Message: “khush raho yaar and live ur btech life full”

Naveen Vyas Email Id: naveen.vyas.86@gmail.com Phone No: +91-120-2774112 Future Plans: “Joining NTPC” BTP: “Finite element analysis of 2-D and 3-D crack problem using Ansys”

based thermal machines”

Message: “IITG offers you excellent oppurtunities for developing all”

50

Message: “Be a part of the HAPPENING events and clubs around you but make sure that academics don’t take a backseat”

Mechanika, 2008

yearbook

Palle Raghavendra Prasad

Pankaj Sharma

Email Id: rvprasad031286@yahoo.

Email Id: pankaj.iit2004@gmail.

co.in

com

Phone No: +91-9440831946

Phone No: +91-9911563332

Future Plans: “Will work in IOCL for

Future Plans: “Schlumberger”

2 years then will go for MS”

BTP: “Investigation of scale effects

BTP: “Experimental study and analy-

in circulating fluidized beds”

sis of Heat Pipe”

Message: “every individual’s life will be moulded according to the all round performance during the four year stay in IIT. So try your level best to develop your personality”

Message: “Look for all round development but give due improtance to studies”

Priyesh Sinha

R Shiva Nikhil

Email Id: iitian4u@gmail.com

Email Id: sivanikhil.raavi@gmail.

Phone No: +91-551-2342372

com

Future Plans: “Joining Shell”

Phone No: +91-40-23817859

BTP: “Robot Path Planning based on soft computing approaches”

Future Plans: “Field engineer in Schlumberger OFS.”

BTP: “Mesh alignment for internal boundaries”

Message: “years in IIT is a wonderful period of your life.

You will always remember the friends you make, the crazy happenings, incidents, events and achievements. So live these four years to the maximum. But along with everything take care to have a descent academic record”

Ravi Assudani

Message: “Do not run for future leaving pleasures of present”

Ravi Shankar

Email Id: fundooravi338@gmail.com

Email Id: rev4ever@gmail.com

Phone No: +91-141-2395384

Phone No: +91-6012-2561562

Future Plans: “MS/PhD at some univ

Future Plans: “Job in TCS”

in US/UK or job at ANSYS Fluent”

BTP: “Mathematical modeling of

BTP: “Development of a cell centered

discontinuous fibre reinforced polymer composites”

finite volume code for structured meshes and its application to nozzle flows“

Message: “Involve yourself in as much activities as you like though always focusing on Acads. Whenever you require your seniors advice feel free to talk to them”

Rohit Kansay Email Id: gonugunja01@yahoo.com Phone No: +91-1732-223202

Message: “Four years of B.tech will give lots of opportunities, so in spite of always complaining enjoy your life here to its fullest and best of luck for your upcoming life”

Rohit Mittal Email Id: rohit4u.iitg@gmail.com, rohit4u_iitg@yahoo.com

Phone No: +91-1552-268272,

Future Plans: “Joining NTPC”

+91-1552-269372

BTP: “Mathematical modeling of

Future Plans: “Joining NTPC or

discontinuous fibre reinforced polymer composites”

Future First”

BTP: “Robot Path Planning based on soft computing approaches”

Message: “study n rest of time enjoy DC++, CS”

Mechanika, 2008

Message: “Always believe in your self. You can do any thing if you want to do it so never ever afraid of doing right thing.

Last but not the least enjoy precious college days”

51

yearbook

Sanjeev Kumar

Satish Mittal

Email Id: sanjeev.sanjuk@gmail.com

Email Id: “mittalsatish2000@gmail.

Phone No: +91-612-2576273

com, mittalsatish2000@yahoo.co.in”

Future Plans: “Will Join BPCL”

Phone No: +91-1552-268829

BTP: “Investigation of Segregation in

Future Plans: “will do a job in Delhi/ NCR company might be Headstrong”

Centrifugal Casting”

BTP: “Design and Fabrication of Active Magnetic Bearing to Control Rotor Vibrations”

Message: “tough times never last but tough people do”

Message: “Do not follow anyone blindly, just do things of your interests n follow them as you can even work for 24 hrs if you have an interest aur bas khaao piyo masti karo..”

Saurabh Garg

Shamit Shrivastava

Email Id: sgarg1985@gmail.com

Email Id: shrivastava.shamit@gmail.

Phone No: +91-9896020478

com

Future Plans: “Joining L&T, Mumbai”

Phone No: +91-11-27551771

BTP: “Design & Manufacturing of a

Future Plans: “I will go for a PhD if I get the fellowship otherwise EIL”

passive IR detector using pyro-electric matls”

BTP: “Strategic Confinement of Evaporating Sessile Drop Using Micro spheres for Controlled Nanosphere assembly for Regenerative Applications and Lab on Chip Techniques”

Message: “Work upon your communication skills, they are a big factor be it IIM or Placement interview”

Sourabh Agarwal

Sourabh Boruah

Email Id: cynide123@gmail.com

Email Id: sourabhboruah@gmail.com

Phone No: +91-374-2333692

Phone No: +91-361-2674537

Future Plans: “may either go to

Future Plans: “need a break, i’ll do

Netherland (TU/e), Canada (UWO) or EIL”

some job”

BTP: “Computer Aided Assembly Process Planning”

BTP: “Design & Manufacturing of a passive IR detector using pyro-electric matls”

Message: “stop reading your seniors’ messages. Stop being

Message: “chill”

like others, be yourself and chill dude!!!”

Sulabh Kakkar

Sumanth Dontharaju

Email Id: sulabh.kak@gmail.com

Email Id: blackstreetboy@gmail.com

Phone No: +91-1662-321400

Phone No: +91-9963083350

Future Plans: “will join RIL or some

Future Plans: “Joining HAL”

MBA college”

BTP: “Mesh alignment for internal boundaries”

BTP: “Experimental Investigation of mixed mode fracture mechanics”

Message: “An F grade doesnot necessarily imply the end of your career prospects. Keep you head up and things would turn out to be good eventually”

52

Message: “These 4 years at IITG will be the best part of ones academic life, so have as much fun as possible, dont neglect acads and make the best of the opputunities available”

Mechanika, 2008

yearbook

Uma Maheshwar Vattikuti

Vijay Kumar Verma

Email Id: vumahesh1@gmail.com

Email Id: vkverma352@gmail.com

Phone No: +91-8852-236767

Phone No: +91-9305067880

Future Plans: “Job in Evalue serve”

Future Plans: “Job in Coal India”

BTP: “Finite Element Analysis of Hip

BTP: “Investigation of Segregation in

prosthesis”

Centrifugal Casting”

Message: “Define a goal and go for it no matter what. Never travel without one“

Message: “take care for your acads and make it your first priority along with some other extra curricular activities only if you find some time for the same. Try hard and harder“

Vinay Mathur

Vivek Bharti

Email Id: viniitg353@gmail.com

Email Id: vivek.iitg@gmail.com

Phone No: +91-141-2759363

Phone No: +91-515-2830369

Future Plans: “Joining NTPC”

Future Plans: “will Join NTPC”

BTP: “Computation of heat transfer in

BTP: “Computation of heat transfer in Taper Pin Fin heat exchanger”

Taper Pin Fin heat exchanger”

Message: “be confident in your b.tech curriculum, you may not acheive anything but donot lose youself in trying to do the same”

Message: “Work hard on English and your communication skills if you really want to achieve high in life”

Yambem Volga Singh

Varun Choudhary

Email Id: lmsvyambem@gmail.com

Email Id: varunchoudhary.16@gmail.

Phone No: +91-3848-261268

com

Future Plans: “NTPC”

Phone No: +91-9910889778 Future Plans: “going to try for the

BTP: “Investigation of scale effects in circulating fluidized beds”

drummer’s post for PDV or superfuzz and enroll for a sound engineering course”

BTP: “Design & fabrication of different types of bicycle carriers” Message: “enjoy the stay here in IITG”

Message: “Carpe Diem Baby…”

Anjan Jyoti Hira Email Id: anjanhira@gmail.com Phone No: 03672-271037 Future Plans: “I never think of the future. It comes soon enough”

BTP: “Design & fabrication of different types of bicycle carriers”

Message: Be happy and optimistic. You all are “Taare zameen par”

Mechanika, 2008

53

Alumni Speaks Rahul Swarnkar better known as GoldCar among his peers, the very first president of MESA, passed out as a Mechanical Engineer in 2006. He is sharing his words of wisdom with us.

Q Presently, what are you doing?

Recently in December, 2007 I completed my Masters in Mechanical Engineering at the University of British Columbia (UBC) in Vancouver, Canada. I was fortunate to get a job offer from Kiewit Corporation. The job starts from March 31 and I’ll be working in Edmonton as a Mechanical/Field Engineer.

Q

Tell us about your journey after graduation from IITG. Life has been even more exciting for me since my graduation. Soon after my graduation I joined a software company, Contata Solutions Pvt Ltd, in Noida, India and worked there for about two months. Although the company was good, I didn’t really like the software job.

Two months later I went on to pursue Masters in Mechanical Engineering at the University of British Columbia (UBC) in Vancouver, Canada. I completed it quite recently in December 2007.

My post-graduation at UBC was a great learning experience for me, both socially and professionally. This is the long and short of my life after graduation from IITG.

Q How is your present life different from life @IITG? My life changed a lot when I moved to Canada. I made new friends from different backgrounds & ethnicities and learned a lot from them. Plus life is always very pleasing and exotic in a big city like Vancouver. Personalitywise, I’m more liberal now.

54

Q How do you maintain contacts with your fellow IIT batch mates and how often you meet?

I maintain my contacts using Orkut and GTalk. It’s very difficult to meet personally during the early years of career when everybody is busy with their jobs/post-graduations.

Q What do you miss the most about your life @IITG? I can never forget those night-outs full of meaningless discussions. However, I highly recommend readers to refrain from doing any such activity.

Q What do you do apart form your professional/ academic life?

I like hanging out with my friends, swimming and visiting new places. I don’t really read much though. If worst come to worst I just go to the downtown or to the beach for a walk.

Q What are your future plans?

Immediate future plan is to work for Kiewit Corporation and gain some North American work experience (Kiewit operates in USA & Canada). Long term plan is to be-

come a designated Professional Engineer in Canada. This takes around 3-4 years and allows one to practice engineering profession without any supervision. There is a slim chance that I might go for an MBA degree after 5-8 years. Only time will tell.

Mechanika, 2008

Q What role in your opinion MESA can play in an institute like IITG? Give us your suggestions so that we can improve.

First of all let me thank all of you for taking MESA to the next level. It is really important that we keep the spirit of MESA alive and consistently strive for improvement. I believe that my affiliation with MESA is something that I’ll cherish for the rest of my life.

Secondly a suggestion; I think MESA and other student associations at IITG e.g., CSEA, Cepstrum etc. should operate in harmony with each other.

This can significantly catalyze their growth.

Q Any message to your juniors?

Each one of you has a great potential and you guys must focus more on things that really interest you. The worst thing you could do to your career is being in a job that doesn’t interest you. Things are getting better for skilled professionals (especially engineers) around the world.

Companies are willing to do anything to get the “right candidates” in their team. Even the top employers don’t want the smartest or the brightest, but the most compatible ones.

The IIT Life With head held high and entering IIT, Expectation in the heart and pride in the eyes, Thinking this perfect life to be All laughter and no cries.

Classes go on and so do the games, Involved in a hundred activities but work; Thoughts of the future going up in flames, Forgetting worry and getting into the IIT quirk.

The reality of life sets in soon, Realizing life isn’t a bed of roses; Beautiful from a distance – like the moon, With some honesty and some poses.

Hating the food but loving the hills, Hating the work but loving the friends, Hating the humidity but loving the chills, The experiences of life are without ends.

Life feels hard, away from home Amidst people of a thousand type, Nostalgic thoughts all free to roam, Depressed with the IIT hype.

In the end, looking back upon these years, So much growth but not without strife; The end brings eyes filled with tears, Because these are the best moments of life.

by Siddharth Kalla

Mechanika, 2008

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Mechanika, 2008