Flow visualation of three-dimensional effects in a cavity flow

Abstract

This paper discusses visualisation of three-dimensional flow about a cavity at low Reynolds number. The length-to-depth ratio was six while the length-to-span ration was three, classifying it as an open, three-dimensional cavity flow, typical of an aircraft weapons bay. The paper discusses the interaction of the shear/mixing layer with the side wall of the cavity. At very low Reyolds number the thickness of the mixing layer over the cavity is significant compared with the span of the cavity. Therefore, a mixing region with a periodic structure forms at the sides of the cavity. The main original finding is that this structure is explained by the interaction of sequential shear layer vortices with each other, with the side wall of the cavity and with the flat plate adjacent to the side of the cavity.