Cavity Flow Assessment Using Advanced Turbulence Methods

Abstract

The vortex shedding generated by compressible subsonic flow interacting with a wall cavity has been investigated using large-eddy-simulation-based turbulence techniques embedded within a legacy Reynolds-averaged Navier– Stokes solver. Cavity simulations using hybrid turbulence approaches seek the accuracy of large-eddy simulation by providing filtering andmodeling of subgrid-scale turbulence with the cost of traditional Reynolds-averaged Navier– Stokes. Simulations applying differing techniques of hybridization of the Menter k-! shear stress transport Reynolds-averaged Navier–Stokes approach include detached eddy simulation (DES-SST), blended subgrid-scale turbulencemodels (GT-HRLES), and a self-adjusting large-eddy-simulation–very-large-eddy-simulation technique (KES) provide an understanding of differing hybrid approaches. Cavity flow results from Reynolds-averaged Navier–Stokes and hybrid simulations are compared with experiment and large-eddy simulation predictions. Evaluation of important flow characteristics illustrates the abilities of these advanced turbulence modeling techniques comparedwith traditional Reynolds-averagedNavier–Stokesmodels. Examination of the influence of the grid, time step, and simulation period demonstrates the sensitivity of the aerodynamic and aeroacoustic predictions to these parameters. In particular the subgrid-scale blended model, GT-HRLES, shows significant improvement in the ability to capture the acoustic signatures and flowfield features on a Reynolds-averaged Navier–Stokes or very-large-eddy-simulation grid compared with the other models.