Abstract
Predicting of vehicle’s performance (acceleration, fuel consumption, pollution etc) is one of the key factors in the design process. In order to estimate it, some driving simulations are to be performed. Improvement of fuel consumption has been for many years the most important challenge in automotive development. Speaking about fuel economy, it is a very important problem that really concerns the birth of a new car.
By analyzing the operation of a vehicle during its life, one can see that acceleration process is amongst the very sensitive regimes whose features conditions the vehicle’s behaviour in terms of pleasure of driving, fuel consumption and pollution. On the other hand, a theoretical study of the transient phenomena of internal combustion engines is very difficult because of the complexity of the mechanical, aerodynamical and thermal processes. Consequently, it is imperative to perform some experimental investigations, as well. Demands to make passenger car friendlier to the environment have actually become increasingly more stringent. Also, taking into account the requirements of short development period in the design process, we must develop better simulation processes.
Thus, the purpose of this paper is the dynamic modelling and simulation of a vehicle for reasons of predicting its dynamic performances and fuel consumption during sudden accelerations. In general terms, a vehicle consists in an energy source (e.g. an internal combustion engine), a transmission and a body, thus the model has been thought as a collection of interconnected objects (blocks) that have a well determined physical meaning. This approach is specific to the MATLAB/SimulinkTM software, which was used to perform this simulation.
In order to validate the simulation’s results, the authors rely on experimental acceleration tests obtained on a flywheel engine test bench, property of Conservatoire National des Arts et Métiers from Paris, France.
Keywords: acceleration, simulation, tests, fuel consumption, pollution.