A wave expansion method for acoustic propagation in lined flow ducts

Abstract

Acoustic liners are used extensively in engineering applications, particularly in aero-engines and automotive exhaust systems. In this paper, a flow impedance boundary conditions is introduced into the wave expansion method with the aim of providing an efficient methodology for computing the acoustic propagation through a lined duct with flow. For a potential flow, the boundary layer and the lined wall are included in the discretisation scheme by the Myers flow impedance boundary condition. The acoustic propagation through a flow-impedance tube is computed in order to validate the implementation of the impedance boundary condition in this scheme. The results show that this computationally light methodology provides generally good agreement with the experimental data.

Identifying equivalent sound sources from aeroacoustic simulations using a numerical phased array

“…Otherwise the source terms of the acoustic analogies can be evaluated from the flow quantities, providing a model for the sources. Although well detailed, this model is not straigthforward to use as input to propagation solvers [7,8] as it requires interpolation between the flow and the acoustic mesh, estimations of derivatives etc. In many applications, it can be useful to get a simpler model, which is the motivation behind this work.…”