Computational analysis of air jet wheel deflector for aerodynamic drag reduction of road vehicle

A concept of an air jet wheel deflector is employed to reduce vehicle aerodynamic drag. The drag reduction mechanism of the air jet wheel deflector is as follow: When the vehicle's driving speed is over than predetermined value, the air jet system injects air in the perpendicular direction to the free stream flow. This air jet acts as an air curtain, which reduces the aerodynamic drag by deflecting the free stream flow away from the tire. Feasibility study was performed using state of the art computational fluid dynamics (CFD) technique based on the lattice Boltzmann method. Fabijanic's simple vehicle model is used for the validation of current CFD technique and numerical study of both the conventional wheel deflector and newly proposed air jet wheel deflector. Parametric studies reveal that the air jet wheel deflector system effectually reduces vehicle aerodynamic drag up to 6.4%, while conventional wheel deflector leads to slight diminishment of aerodynamic drag of 3.6%. From this finding, it can be concluded that air jet wheel deflector is a useful device to reduce aerodynamic drag of automobile.