Simulations of Supersonic Jet Noise

Abstract

Numerical simulations are presented for the unsteady flow and noise radiation of high speed circular jets. The predictions are based on solutions of the nonlinear disturbance equations. Only the large-scale fluctuations are resolved. The effects of the small scales are parameterized using a subgrid-scale model. The radiated noise is predicted using both a direct simulation and a Ffowcs Williams–Hawkings method. The effect of the prescription of in-flow conditions and the use of a dynamic subgrid-scale model are described. The choice of these models is shown to effect the predicted far field sound pressure levels. Comparisons are made with experimental measurements. The predictions are in reasonable agreement with the experiments. The reasons for these absolute discrepancies are discussed. Relative changes for different operating conditions are shown to be predicted well. Finally, the simulations are used to describe some statistical properties of the jet turbulence relevant to noise radiation.