Analysis of flow oscillations in an open cavity by a passive control method

Abstract

Numerical simulations are performed to evaluate a submissive controller method, utilised to suppress the pressure oscillation made in an open cavity flow. The open cavity considered in this work has the aspect ratio of 2 (Length of the cavity/Depth of the cavity=2). As the passive control technique, a non-smooth surface is installed, upstream of the cavity. The parameters like flow instability, noise around cavity are investigated using large eddy simulation, coupled with acoustics model, for smooth and non-smooth cases. The experimental and computational data available in literature are utilized for validation of results for the smooth case. By flow visualizations, it is established that locating a non-smooth surface at the upstream effectively suppresses hollow stream oscillations. By comparing the current ground structures in cases of smooth and non-smooth surfaces, the mechanism of oscillation control by non-smooth surface is analysed.