Journal for Research | Volume 02 | Issue 09 | November 2016 ISSN: 2395-7549
Selection of c to Achieve Performance of Vehicle Pankaj Raut B.E Student Department of Mechanical engineering Institute Tata Technologies Ltd.
Abstract Selection of powertrain for vehicle is depends upon vehicle type & application of vehicle. To achieve performance of vehicle, engine torque at maximum revolutions, Transmission ratio, Axle ratio & tire plays important role. In order to understand vehicle performance in theoretical calculation there should be proper selection of power train aggregates. All these aggregates technically will evaluate the actual vehicle performances. For example, trucks are seldom run at their rated maximum speed. In fact, they are usually operated with engine speed at maximum torque or at the speed where fuel consumption is minimized. In climbing hills, there may be occasions when the engine revolution is raised to its maximum to produce the maximum horsepower; however, the most efficient method of operation is to use the range of engine speed, which maximizes torque. If an engine's speed range, producing maximum torque, is extremely narrow, a slight increase of rpm will cause a substantial loss of power and sign of poor performance characteristic. In other words, engines with high maximum torque and horsepower are not necessarily the most "powerful engine." Factors other than the maximum values of the torque and horsepower must be evaluated in determining the practical performance of engines. Furthermore, a high performance engine must be combined with the correct transmission and differential in order to produce the desired running performance. It is necessary to understand the factors affecting its ease of operations. This Paper tells how to integrate powertrain and judge performance of vehicle according to application and type of vehicle by reading performance curves and calculation. Keywords: Powertrain, Vehicle _______________________________________________________________________________________________________ I.
INTRODUCTION
Current scenario of vehicles is to produce more power and better fuel economy. For that care should be taken while power train integration that power loss should not be minimum. For example, a high speed truck for carrying goods applications within intra city. Truck need max speed 100 km/hr but at the same time it is able to carry heavy goods in hilly area or gradient area. Truck mostly runs 90% on flat road. For such application we should optimize the power train integration such that it should get top speed on flat road and max torque on tires in gradient road. To meet vehicle performance, should select an engine whose torque curve is flat with respect engine rpm (see fig 1). Also consider transmission ration, Rear axle ration tire size (table 1) and set Maximum speed of vehicle and % of grade ability. II. OBJECTIVE OF WORK Opportunity
Optimization of power train aggregates Better fuel economy Reduction of engine power loss in gradient road Use the range of engine speed, which maximizes torque Can set Vehicle max speed Customer Impact
Customer satisfaction due to better fuel economy Enhanced grade ability. III. METHODOLOGY: - VEHICLE PERFORMANCE OPTIMIZATION Vehicle speed
To optimize vehicle performance 1st set vehicle application. In this paper vehicle application is cargo vehicle which has to max speed of 103 Km/h. This vehicle run mostly runs 90% on flat road. As per engine curve (Fig 1) and transmission ratio (Table1) we can calculate speed at different gear ratio. Speed at different gear ratio as per equation (Fig 2).
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