Survey of CFD studies on automotive buffeting

In the current automobile market buffeting is one of the customer frequent complaints on luxury cars and SUVs. Buffeting is a low frequency but high level wind noise and makes people inside the vehicle uncomfortable if it lasts for a long period of time. The physical mechanism of buffeting is a complicated phenomenon of aeroacoustic resonance. The aeroacoustic characteristics of buffeting depend on vehicle features and operating conditions. In this paper, a survey of CFD studies on the automotive buffeting is presented. Firstly, several buffeting related concepts, such as Helmholtz resonator, flow over a cavity, shear layer instability and vortex shedding, are reviewed and relevant references are listed. Then, a historic survey of the buffeting investigation is made with emphasis on computational studies. As an example, the buffeting studies at DaimlerChrysler are selected to demonstrate the procedure of CFD simulation for automotive buffeting. The procedure is then validated by the correlation with wind tunnel testing. After that the validated procedure is applied to find solutions for buffeting reduction. Finally, some comments on buffeting studies are addressed. (author)