International Journal of Research and Innovation (IJRI)
International Journal of Research and Innovation (IJRI) 1401-1402
DESIGN AND MATERIAL OPTIMIZATION OF WIND TURBINE BLADE
B.Bhuvaneswara Rao1*, T.Jayananda Kumar2 1 Research Scholar, Department Of Mechanical Engineering, ,G I E T, Rajahmundry, AP, India. 2 Assistant professor , Department Of Mechanical Engineering, ,G I E T, Rajahmundry, AP, India.
Abstract Wind energy is a promising energy source. Modern wind power industry officially started in 1979 in Denmark with a turbine of few KW and its evaluation brought up to now, devices of which rated power is higher than 20 MW. The size of wind turbine’s massively increased and their design achieved a common standard device: Horizontal axis, Three blades, Upwind, Pitch controlled blades, Active yaw system. High hub height and large rotor diameter lead to increased energy output, but mass growth is an unwanted side effect. The goal of this study was to develop and validate a turbine blade using finite element analysis (FEM). In development, single rib and multi ribs are used for validation of strength. Then composite materials were applied on blade for material optimization for maximum weight reduction. With weight reduction side effects will be reduced to achieve the optimized design
*Corresponding Author: B.Bhuvaneswara Rao , Research Scholar, Department Of Mechanical Engineering, G I E T, Rajahmundry, AP, India. Published: September 5, 2014 Review Type: peer reviewed Volume: I, Issue : III
Citation: B.Bhuvaneswara Rao, Research Scholar (2014) DESIGN AND MATERIAL OPTIMIZATION OF
WIND TURBINE BLADE INTRODUCTION Wind energy
Wind is just moving air. This mass, having a certain velocity, owns kinetic energy.The energy can be converted, through a specific device, into a more useful type.Therefore, it is possible to produce electricity, moving parts with mechanical energy,pump water or provide heat for instance. Humans had the first approach with wind power thousands of years ago, propellingtheir sailboats with it. Since the 7th century AD, wind was used by windmills to pumpwater or mill grains in Persia. Wind energy has been adopted for pumping water from wells for steam trains, and itis still able to provide it for isolated houses or off-grid locations.Only at the end of 19th century the concept of modern wind turbine arises, convertingthe kinetic energy of the wind into electricity. Wind energy industry born officially in 1979, with the first serial production ofDanish turbines.
Since then, the trend followed by wind turbine manufacturers was designing biggerdevices. Increasing the diameter of the rotors and using higher towers were the mainpaths followed until now. Turbines with bigger diameters are able to capture morewind; higher towers elevate the rotor out of vegetation and buildings influence,leading to an increased average wind speed. Models from 1979 were having only 12-20 kW of power output; today the largestturbine (Enercon E-126) has a rated power of 7 MW and it is 198 meters high. Nowadays, modern wind turbines achieved a quite common baseline for their design:horizontal axis, 3 blades, upwind, variable speed, pitches controlled and with activeyawing system. Of course then each company prefers to adopt certain materials,different sets of airfoils, rated wind speed or tip wind speed ratio, but the moststraightforward relation to approximate the rated power of a device is from the rotordiameter. Lately it looks like the wind turbine manufacturers approach changed its trend.Making a higher tower and increasing the rotor diameter does not lead to the sameimprovements had until now. Probably, with the current materials and technology, weare close to the maximum size possible (still considering the economic aspect ofcourse).From physics, the power output of a wind turbine P, neglecting gearboxes andgenerators efficiencies, can be described by
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International Journal of Research and Innovation (IJRI)
Where _ [kg/m3] is the air density, S [m2] is the swept area of the rotor (thusS=_D2/4), V [m/s] is the wind speed and cP[-] is the coefficient of performance. Thepower output then scales with the square of the rotor diameter.The mass instead scales with the cube of the rotor diameter, in fact creating a limitabove which increasing the size is not economically profitable anymore. Due totechnology improvements, throughout the years the real coefficients have been 2.155and 2.6, respectively. The new designs focus on other aspects than “size�. For instance, improving theefficiency of the blade reduces the fatigue loads, increasing the life cycleof thecomponents, as well as more accurate internal blade design can reduce the amount ofmaterial utilised, making the rotor lighter and cheaper. Advanced aerodynamic technologies are also embraced to achieve better and cheaperresults.Development of smart rotors, winglets, flaps, gurney flaps, micro tabs and vortexgenerators is a daily basis topic. All these technologies are meant to control or limitthe harmful loads, leading to less fatigue and therefore longer life cycle or lessmaterials.
Blade structural design Actiflow Preliminary Studies
Actiflow already applied successfully active BLS technology on cars and in order toimprove wind tunnel testing. In 2007, Actiflow started focusing on the application ona wind turbine blade. The strong belief in this technology and the knowledge gatheredby parallel applications translated into a patent. This patent describes how the centrifugal effect given by the rotation of the rotorcreates a pressure difference between the two sides of the panel through which suctionoccurs. It does not give a specific final solution or describe a particular blade speciallydesigned for BLS applications. It is rather a collection of thoughts and considerationson how apply this technology, evaluating and giving as example several solutions.For instance, the precise flap wise position on which apply the porous material is notDefined as well as how the room of the internal channels is utilized In addition, the utilization of some slots instead of the porous material surface is takeninto account, as well as how the latter should be applied on the blade Since the application for the patent, internship and graduation projects incollaboration with Delft University of Technology have been developed, refining thechoices of the real possible applications and brightening the achievable improvements.
Enercon E-48, blade tip winglet WhalePower blade leading edge
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International Journal of Research and Innovation (IJRI)
Modeling Of Wind Turbine Blade In Pro/Engineer
Solutions for improving the room of the internalchannel
The above image shows the designing of wind turbine blade first segment
Different ways of creating suction of the boundary layer In 2008, JorritLousberg developed with Actiflow a study about Boundary LayerControl in Wind Turbine Design. Starting using the NREL 5 MW wind turbine as reference, he firstly analysed theapplication of BLS at root sections of the wind turbine blades, showing that theairfoils are benefiting from this technology, by means of improved polars computedby RFOILsuc. Secondarily, he confirmed this founding with an aero-elastic code(NREL’s FAST), highlighting the improvements of those sections by the powercoefficient cP. He further analysed to what extent BLS and BLB (Boundary Layer Blowing) canprovide load control of the sections towards the tip, contributing the most to the rootbending moments. It was found that first of all the centrifugal effect of those sectionsis not enough for a BLS passive system; an extra pump is needed in order to suck(and/or blow) the air through the porous material (and/or the openings), or asophisticated system of valves. The benefits this load control can provide are notextremely relevant concerning BLS, whilst BLB allows a sensitive load reduction,which can be employed for example during gusts, although producing extra drag.Further investigation in this aspect was needed before establishing the real advantagesof this kind of control. Lousberg’s preliminary study has a chapter about “Potential for StructuralImprovement by BLS”. He found that given a reference airfoil, increasing its heightand applying BLS on the suction side, was leading to an airfoil with betterperformances than the reference itself. The new thicker shape has an improvedmoment of inertia and stiffness, allowing the usage of fewer materials and resultingon a cheaper and lighter blade.
The above image shows the designing of wind turbine blade rare view
The above image shows the standard blade section for analysis purpose
The above image shows the single rib blade section for analysis purpose 28
International Journal of Research and Innovation (IJRI)
Introduction To Ansys ANSYS is general-purpose finite element analysis (FEA) software package. Finite Element Analysis is a numerical method of deconstructing a complex system into very small pieces (of user-designated size) called elements. The software implements equations that govern the behaviour of these elements and solves them all; creating a comprehensive explanation of how the system acts as a whole. These results then can be presented in tabulated, or graphical forms. This type of analysis is typically used for the design and optimization of a system far too complex to analyze by hand. Systems that may fit into this category are too complex due to their geometry, scale, or governing equations. ANSYS provides a cost-effective way to explore the performance of products or processes in a virtual environment. This type of product development is termed virtual prototyping.
The above image shows thedisplacement
Structural Analysis of wind turbine blade
The above image shows the Von-misses stress Analysis of wind turbine blade wing using Eglass with single rib
The above image is showing imported model from pro-e to the format of (IGES) Initial Graphics Exchange Specification
The above image shows the displacement 29
International Journal of Research and Innovation (IJRI)
S2-Glass
The above image shows the Von-misses stress Structural Analysis of wind turbine blade wing using E-glass with dual rib
Hallow section
Single rib
Dual rib
Displacement
0.022
0.022
0.022
Stress
12.842
12.736
12.995
Mode1
1.862
1.847
1.864
Mode2
1.919
1.917
1.923
Mode3
1.587
1.580
1.595
Mode4
1.826
1.821
1.848
Mode5
1.460
1.462
1.008
DISCUSSIONS • The project work is done to suggest optimum blade design and suitable material to minimize the weight to get maximum output from the wind turbine. • Weight is one of the major criteria which effect in power generation using wind power. • In this project different types of cross sections are analyzed with change of rib sections and also two composite materials are used to analyze the blade sections. • These E glass (FRP) & S2-glass (ERP) materials are having low density value than traditional materials. • As per the analytical results single rib is showing good structural and frequency characteristics. • So better to use single rib section for wind turbine blade. • While comparing the materials S2 glass is showing better structural stability than E glass.
The above image shows the displacement CONCLUSION This project work deals with turbine blade inner section design modification and material replacement of the traditional material for the maximum weight reduction to obtain maximum output from the turbine.
The above image shows the Von-misses stress E-Glass Hallow section
Single rib
Dual rib
Displacement
0.027
0.027
0.027
Stress
13.286
12.829
13.069
Mode1
1.806
1.799
1.815
Mode2
1.872
1.867
1.874
Mode3
1.549
1.539
1.553
Mode4
1.777
1.775
1.801
Mode5
1.412
1.422
1.409
Initially literature survey is done on wind turbine blade to design and optimization for further safety. Full blade and blade section modeling is done using pro-engineering , blade sections are generated in surface module also for the purpose of analysis using material matrix (layers) method. Static and modal analysis is done on standard single rib and two rib sections using shell element with “5” layer with 90O, 45O, 0O, - 45O, 90O orientation in material matrix. As per the analytical results single rib section is better than standard and two rib sections, S2-glass epoxy and E-glass epoxy both materials are having nearest values.( S2 is having little bit high strength than E-glass). According to the above results and discussion this project work concludes that single rib section wind turbine blade along with E-glass epoxy is the better option , because of good structural stability , low frequency, and low cost than S2-glass.
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International Journal of Research and Innovation (IJRI)
REFERENCES
Author
1) Model Validation And Structural Analysis Of A Small Wind Turbine blade 2) Structural design and analysis of a 10 MW wind turbine blade Kevin Cox, PhD Candidate, Dept. of Engineering Design and Materials NTNU 3) Structural Design of a 5 MW Wind Turbine Blade Equipped with Boundary Layer Suction TechnologyAnalysis and lay-up optimization applying a promising technologyFederico Ghedin 4) Hermann Glauert FRS, FRAeS J. A. D. AckroydFormer Aerospace Division Manchester School of EngineeringVictoria University of Manchester, UK
B.Bhuvaneswara Rao1*, Research Scholar, Department Of Mechanical Engineering, G I E T, Rajahmundry, AP, India.
T.Jayananda Kumar2 Assistant professor , Department Of Mechanical Engineering, ,G I E T, Rajahmundry, AP, India.
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