Towards overset LES for aeroacoustic source prediction

Abstract

In this contribution an application of a computational aeroacoustics code (CAA) as a hybrid Zonal DNS tool is presented. The here used hybrid approach is based on a novel implementation of the Non-Linear Perturbation Equations (NLPE) extended with viscous terms, denoted as overset since a perturbation analysis is performed on top of a background flow. It is found that Direct Noise Computation results of a cylinder in uniform flow show the dipolar sound radiation characteristic as well as the expected decay of sound pressure level with distance. The extension to LES is illustrated with isotropic decaying turbulence, where the expected -5/3 slope of the reference DNS data is recovered with the LES employing the classical Smagorinsky model.