High speed jet noise simulations for noncircular nozzles

This paper describes a simulation of a supersonic elliptic jet. The jet geometry and operating conditions are chosen to match available experimental data. The formulation of the problem in terms of the Nonlinear Disturbance Equations is described. The numerical algorithms and parallel implementation are also described. Results are presented for the mean flow development. Comparisons are made between the predicted and measured Sound Pressure Levels and Perceived Noise Levels. The agreement is good in the peak noise direction though it deteriorates at larger angles to the jet downstream axis. No significant difference is observed between the Perceived Noise Levels in the major and minor axis planes. Two-point space time cross correlations are determined for the axial velocity fluctuations. The convection velocity obtained from these correlations is in agreement with previous observations at lower Mach numbers and is compatible with the peak noise radiation directions.