Abstract:

An orthogonal test for wake structures was conducted with computational fluid dynamics (CFD) technique to optimize the stepping automotive wake flow field. The method of controlling variable was applied to analyze six main rear structures, and the factor level was preferred. The L25 (56) orthogonal optimization test of
the tail structure method was designed. And the degree of influence from different rear structures was analyzed by use of the range analysis method. The wake flow field of the optimum tail model was obtained. The results show that the wake structure comprehensive optimization decreases the coefficient of the aerodynamic drag by 14.4%. The wake flow structure is improved as the rear airflow was separated and vortexes were suppressed effectively. These results provide an important basis for the optimal design of automotive wake shape.

Key words: automotive rear structure, wake flow field, computational fluid dynamics (CFD), orthogonal experimental design