A convected frequency-domain equivalent source approach for aeroacoustic scattering prediction of sources in a moving medium

In this paper, a convected frequency-domain approach for acoustic scattering prediction is
suggested, for sources and scattering surfaces in a uniform constant flow. Frequencydomain
moving-medium formulations are used for prediction of the incident acoustic
pressure and acoustic pressure gradient. The latter is required for evaluation of the
hardwall boundary condition in a moving medium and allows a convected definition of the
equivalent sources. The scattering approach is validated by the analytical case of scattering
of a pulsating monopole source by a rigid sphere. The applicability of the methodology to
moving-medium problems is demonstrated for rotating and pulsating monopole point
sources in a uniform flow, located near an infinite flat scattering surface. The suggested
approach allows frequency-domain scattering predictions for sources in a uniform constant
flow of any subsonic velocity, enabling direct inclusion of convection effects on
incident and scattered acoustics. The hardwall boundary condition is thus evaluated
directly in a moving medium. The need for a Lorentz transform is obviated, overcoming the
complexity it introduces and the limitations it imposes.

Publication year:2018

Keywords:Acoustic pressure gradient, Acoustic scattering, Computational aeroacoustics, Equivalent sources, Moving medium

BOF-keylabel:yes

BOF-publication weight:1

CSS-citation score:1

Authors:International

Authors from:Higher Education

Accessibility:Open