Analysis of the Influence of Changes in the Exterior Elements of the Car on the Drag Coefficient and the Problem of Its Optimization

Abstract

The results of optimization of the external aerodynamic surface of the car in order to reduce the drag coefficient by making changes in its shape and do not affect the overall stylistic appearance are presented. The optimality criterion is the coefficient of longitudinal aerodynamic drag Cd, while the optimization parameters are the geometric characteristics and the appearance of the car, which was developed by stylists. Computational procedure and an algorithm for solving an optimal problem are presented. We emphasize that the problem of calculating the aerodynamic drag coefficient Cd, taken separately, is a difficult and very computationally resource-intensive task of applied aerodynamics. Also note that the problem of optimizing (minimizing) the Cd coefficient includes the task of calculating one as a procedure, repeated at each step of the iterative optimization process, when the above-mentioned optimization parameters are changed. Obviously, the considered optimal task is relevant, since, having solved it, it is possible to increase the driving distance of the car, reduce the generation of noise generated by its various parts and preserve the external aesthetic appearance developed by designers. The last point is particularly important, as usually when designing a car, its creation process is iterative in nature when interacting with groups of designers and development engineers. The approach presented in the paper will reduce the time and number of such iterations.