Flow-induced vibration in the compressible cavity flow

The cavity plays an important role in the fuel-air mixing and combustion stability inside the hypersonic scramjet. However, the high levels of time-dependent loading resulting from the supersonic cavity flow can cause intense structural vibration even damage. Experiments and numerical simulations were performed to understand the complex fluid-structure interaction in this paper. A cantilever plate with a cavity was installed as a splitter plate in the supersonic mixing layer wind tunnel. The response displacements of this cantilever plate were measured by a non-intrusive laser vibrometer. Large eddy simulation (LES) was applied to calculate the aerodynamic loading. Results show that the St number of time-dependent surface-averaged pressure difference agrees well with semi-empirical relation of Heller used to predict the resonance mode. The cantilever plate exhibits a directly dependent response to self-oscillation of supersonic cavity flow. Measurement results of displacement indicate that the vibration shape of this plate is dominantly two-dimensional