A Flow/Acoustics Interaction Method for the Prediction of Sound Propagation

Abstract

Traditional Computational Fluid Dynamics (CFD) methods face accuracy and computing expense problems when dealing with aeroacoustic applications. A new formulation of the governing equations of inviscid compressible flow suitable for aeroacoustic simulations is presented. The flow variables of the Euler equations are split into a compressible unsteady flow part and an acoustics part making the assumption that the propagation of sound does not affect the flow field. Separate systems of equations, which allow for the unsteady interaction between the flow and acoustic fields, are obtained. These equations are solved using a simple, low order and low cost numerical scheme. The superior capability to resolve the sound field compared to a traditional CFD method is shown. For the evaluation of the method, an acoustic diffraction problem is solved and Flow/Acoustics Interaction Method results are compared to the linear analytical solution. The method captures the dynamic interaction between the flow and acoustic fields.