Overset-LES with stochastic forcing for sound source simulation

Abstract

An application of a hybrid RANS/LES method to trailing-edge noise, is presented in this contribution. The numerical framework of the CAA-code PIANO offers a basis for extending the Non-Linear Perturbation equations with viscous terms. As a result, a full Navier-Stokes equations perturbation analysis, denoted with “Overset”, can be performed on top of a steady background flow. With such a scale-resolving simulation tool, consisting of optimized higher-order numerical schemes for aeroacoustics, the investigation of sound source mechanism on first principals become feasible. An issue of such hybrid zonal approaches, namely the seeding of proper inflow turbulence, is solved with the Fast Random Particle-Mesh method in combination with the Eddy-Relaxation source term. The overall process chain of the intended Overset-LES usage is illustrated by means of NACA0012 trailing-edge noise computations at moderate Reynolds number and zero angle-of-attack.