The outflow field of a simplified fast back car was simulated numerically with the effect of no cross wind

steady cross wind and unsteady cross wind.The aerodynamic forces and coefficients were calculated.The results show that

steady crosswind will generate bigger lateral force

and also increase the drag and lifting force to a certain extent;the change trend of aerodynamic forces was the same as that of lateral wind speed.With the effect of unsteady cross wind

the drag increases more slightly

and the lateral force increases most significantly;the lifting force remains moderately.When cross wind reaches a high level

the flow field will change dramatically

and the wake vortex is turned into side vortex.