Study on the aerodynamic noise of a fastback car with rear view mirrors in uniform motion and accelerated motion

The flow field around a simplified fastback car with rear view mirrors and aerodynamic noise at some receiving point were numerically simulated and analyzed using CFD(Computational fluid dynamics) software FLUENT.The pulsating flow field was simulated by the large eddy turbulence model and the momentum equations were discretized with the unbounded central difference scheme.The calculations were performed under three conditions: uniform motion with two running speeds and accelerated motion.The influences of pulsating flow field and aerodynamic noise by uniform motion speed,uniform and accelerated motions were investigated.The results show that with the increase of uniform motion speed,the velocity,amplitude of pulsating pressure,sound pressure level corresponding to each frequency and total sound pressure level at the receiving point become bigger,the pressure becomes smaller;at the same motion speed,the velocity,sound pressure level corresponding to each frequency and total sound pressure level in accelerated motion are greater than those in uniform motion,the pressure is smaller.