Passive Control Strategies for Transonic and Supersonic Flows Over Cavities

High-speed flows over open cavities are prevalent in many applications mainly related to aerospace engineering. Bay cavities of combat aircraft, for example, are subject to transonic or supersonic flows that can be accompanied by intense pressure fluctuations produced by shear-layer instabilities, flow separation, the formation of vortex structures, or shock wave boundary interaction. Thus, the analysis and accurate prediction of the transonic and supersonic flows developing over cavities is of significant importance from theoretical, numerical and experimental standpoints. In this paper, we investigate several passive control strategies aimed at reducing noise generation and propagation in the context of both transonic and supersonic flows over a rectangular cavity. This paper focuses on spoilers positioned at the leading edge of the cavity tested parallel to the flow direction. The spoilers include generic patterns, such as sawtooth and rectangular structures, which are modeled using conformal mesh, while preliminary testing of fractal-like structures modeled via an immersed boundary method is underway. The results show that that these types of spoilers are able to reduce pressure fluctuations both inside and outside of the cavity.