Prediction of Oscillation Frequencies for Unstable Flow Past Cavities

Abstract

The incompressible flow of a shear layer past a cavity can undergo relatively large amplitude organized transverse oscillations which arise from hydrodynamic instability. A model which enables prediction of the oscillation frequencies by accounting for streamwise variations in wave number and amplification factor is put forth. Predicted frequencies compare well with experimental data over a tenfold range of dimensionless cavity length.