Efficient Scale-Resolving Simulations of Open Cavity Flows for Straight and Sideslip Conditions

Abstract

This study aims to facilitate a physical understanding of resonating cavity flows with efficient numerical treatments of turbulence. It reinforces the efficiency and affordability of scale-adaptive numerical techniques for simulating open cavity flows with a separated shear layer consisting of a wide range of flow scales. Visualization of the resonant modes occurring due to the acoustic feedback loop aids in a better understanding of large-scale flow oscillations. Under this scope, scale-adaptive simulation (SAS) based on the k-ω SST RANS model with different turbulence treatments has been studied for an open cavity configuration with a length-to-depth (L/D) ratio of 5.7 featuring Mach number (Ma) 0.8 and Reynolds number (Re) 12×106. It is shown that the essential cavity flow physics has been captured using the SAS approach with more than 90% improved computational efficiency compared to commonly used hybrid RANS-LES approaches. In addition, wall-modeled SAS when supplemented with an artificial forcing concept to trigger the model provides very good spectral estimates comparable with hybrid RANS-LES results. Following the validation of numerical approaches, the directional dependence of the cavity resonance is investigated under asymmetric flow conditions, and spanwise interference of waves due to the lateral walls of the cavity has been observed.