Direct Simulation of Aeroacoustics

Abstract

Direct simulation of both fluid flow and noise within one numerical calculation offers a valuable means of testing the validity and applicability of aeroacoustic theories and analogies because one does not suffer from uncertainties concerning the empirical modelling of aeroacoustic source terms. To reduce computational costs we propose to apply domain decomposition methods. The linearised Euler equations are used in the regime where nonlinear effects can be neglected. Furthermore different grids and time steps are used in each domain, thus leading to a much more efficient code. The main difficulty here is to avoid non-physical reflections at the artificial interface between different mathematical models, grids and numerical methods. In this paper a new idea is presented, how to reduce these reflections by two orders of magnitude. We restrict ourselves to one space dimension.