RANS and DES turbulence model predictions of noise on the M219 cavity at M=0.85

摘要

Two rectangular cavity configurations, with and without bay doors, at Mach 0.85 are investigated with the objective of assessing the ability of 3D CFD with advanced turbulence modelling to predict narrowband and broadband flow noise. A non-linear, two-equation, eddy-viscosity model run in unsteady mode (URANS) is compared with Detached Eddy Simulation (DES) on a cavity with a L/D ratio of 5. In a thorough evaluation, comparisons are made between DES variants published in the literature, namely Spalart-Allmaras, k-ε and k-ω-SST. We also assess the effect on the noise spectra of using different CFD prediction time-samples of approximately 100 flow passes compared with 250 flow passes. Detailed experimental data for both cavity configurations provide a valuable opportunity to compare the predicted spectra at many points along the cavity ceiling and band-limited amplitude along the cavity length. We conclude that for such cavity flows, all DES models perform similarly well and are superior to unsteady RANS due to their inherent ability to resolve broadband structures.