Effect of Static Control Device on Suppression of Cavity Noise

Abstract

This paper describes the effect of a thin plate as a static controlling device to suppress cavity noise when it is inserted vertically into a cavity. Experiments using small and large wind tunnels are carried out to investigate the size effect of the cavity model. As a result, it is shown that there are two optimum plate locations for the noise reduction. One is near the upstream edge and the other is just in front of the downstream edge. By comparing the experiments at small and large wind tunnels, it is found that in the large wind tunnel, noise reduction is not so effective as in the small one.