Lattice Boltzmann Simulations of a Supersonic Cavity

Abstract

Unsteady simulations using PowerFLOW, a Lattice-Boltzmann-method-based solver, of a rectangular deep (L/D= 4.5), open-flow cavity at subsonic and supersonic speeds (M= 0.6 to 1.5) are presented. Acoustic sound pressure levels and cavity modes are compared to experiments and analytical models. The simulations show a good quantitative and qualitative agreement with the experiments for the spectra at various probes located in and around the cavity. The shear layer mode is characterized by Rossiter modes and the frequencies are well predicted. The three-dimensionality in the flow is also identified by the presence of lateral pressure gradients, resulting in the interaction of lateral and longitudinal modes.