Influence of Impinging Wall Ramping Modification on the Flow Field of Open Cavity at M = 2.0

Abstract

Studies were made to understand the flow features around an open cavity at Mach 2.0 corresponding to Re = 0.55 × 106 based on the cavity depth. Experiments were carried out using a blowdown type supersonic wind tunnel having a test section size of 50 mm × 100 mm. Oil flow and schlieren flow visualization were made to understand the steady flow features inside the cavity. Unsteady pressures were measured at several locations to obtain the fluctuating flow field details and the pressure spectrum. Impinging wall modifications of the cavity were made with an objective to reduce the Rossiter's mode frequencies and its amplitude. Partial ramping of the impinging wall with variations in height and angles were made. With adoption of a specific combination of the impinging wall height and angle, the first two modes of the multiple tonal characteristics could be reduced significantly. The present adopted method could result in 74% reduction of root-mean-square (RMS) pressure and a noise reduction of 11 dB.