Predicting high-speed feedback mechanisms in rectangular cavities using lattice-Boltzmann very-large eddy simulations

摘要

Aeroacoustic feedback mechanisms in rectangular cavities are strongly dependent on length-to-depth ratio and free stream velocity. The capability to predict the effects of these parameters using a scale-resolving transonic lattice-Boltzmann flow simulations is assessed, for the first time, by considering the M219 benchmark configuration for two different length-to-depth ratios (10:1 and 5:1) and two free-stream Mach numbers (0.85 and 1.35). Numerical results are compared and validated using unsteady wall pressure measured in wind tunnel tests. Tonal and broadband components of the pressure fluctuations are properly captured. For the shallow cavity configuration, an increase in Mach number is found to enhance the development of Rossiter modes inside the cavity. A more detailed analysis of these Rossiter modes is carried out for the shallow cavity at supersonic speed, for which physical insight is gained through the usage of spectral proper-orthogonal decomposition and wavelet/Fourier analyses. (C) 2021 Elsevier Masson SAS. All rights reserved.