Open cavities an aircraft exposed to high-speed flow, such as weapon bays, can give rise to intense selfinduced pressure oscillations. The amplitude of these oscillations, under certain flight conditions, can cause structural damage. Substantial experimental and analytical efforts have investigated these pressure fluctuations, resulting in some understanding of the complex interaction of the external shear layer and cavity acoustical disturbances. However, no numerical computations have been obtained for the complete governing fluid mechanical equations. The purpose of this study is to obtain numerical solutions of the Navier-Stokes equations for an open cavity in order to provide a new tool for the analysis of this phenomenon. '