Experimental and Numerical Study of Flow over a Cavity for Reduction of Buffeting Noise

Experimental and numerical investigations are conducted to investigate the noise induced by a subsonic flow over a cavity. Particular attention is focused on the problem of low-frequency pressure oscillations inside the cabins of automobiles with open sunroofs. The mechanisms of buffeting noise are examined by considering a model cavity. Extensive experiments are performed to validate the computational scheme developed in the present study. This computational scheme is used for designing generic deflectors for reducing buffeting noise. Experimental and computational results show that the traditional generic deflector is unable to reduce the buffeting noise when the flow velocity is sufficiently high. However, a vented deflector allows the effective control of the buffeting noise at relatively high flow speeds.