Numerical Evaluation of URANS/Zonal-DES Models in the Acoustic Prediction of a High Reynolds Compressible Open Cavity Flow

The direct prediction of acoustic sources requires the numerical integration of the unsteady compressible Navier-Stokes equations in complex geometries. The acoustic sources are extracted from the numerical solution and then injected as a source term in a hybrid methodology. Obtaining the small acoustic scales demands very fine meshes where a statistically converged solution has been obtained. Recently, the efforts of the numerical community have been directed towards the application of Large Eddy Simulation to predict aeroacoustic sources. In this kind of predictions, good compromise with experimental results is obtained, however, it is recognized that the computational cost of this kind of simulations is still excessive, and less demanding solutions become essential. Nevertheless, adequate calibration of 2D or 3D computations with standard turbulence models is expensive, and although in use, it is not clear that their solutions can be as precise as those obtained with LES. In this work, the numerical evaluation of different methodologies and their impact on aeroacoustic prediction is investigated. Two and three dimensional flows and different types of turbulence models are considered in an open cavity flow problem at Mach number of 0.8 and Reynolds number of 8.6 · 105, for which an extensive experimental analysis has been performed by other authors.