Study the effect of rear spoiler on car aerodynamics characteristics

Taking CFD software as the platform and the car as the research object, the air´s resistance coefficients and speed are solved by using RNG k-ε equations and dynamic mesh method. The finite volume method is used to discrete the governing equations, the second-order up wind difference scheme is adopted for the convection term and the centric difference scheme for the dissipation term. The discretion of time is carried out by a full-implicit time integral scheme. PISO algorithm is adopted to the transient numerical simulation. The influence law of automobile air flow in the rear and its turbulence on car aerodynamics characteristics with or without a spoiler is achieved. The simulation results are consistent with the test ones. It is proved that the numerical simulation of automobile air flow with dynamic grid in CFD software is feasible, and which provides the references for the development of automotive products with spoiler.