Nonreflecting zonal characteristic boundary condition for direct numerical simulation of aerodynamic sound

Abstract

A nonreflecting zonal boundary condition was presented for direct numerical simulation of aerodynamic sound. The method is based on commonly used characteristic boundary conditions and, therefore, only requires marginal modifications to existing codes. It was shown that the proposed zonal boundary condition succeeds in significantly reducing spurious pressure oscillations that are produced when vortical structures in compressible flow cross the far-field boundaries. The aim of these simulations was to evaluate the acoustic scattering of Tollmien-Schlichting (T-S) waves convecting over the trailing edge(TE).