Application of Body Force Concept in Aeroacoustics
Date:
[Abstract] This paper is to present the application of body force concept in the immersed boundary (IB) method to aeroacoustics problems. Five kinds of body force models are given to model wall boundary conditions in a highorder in-house solver for the computational aeroacoustics. The body force models are evaluated by simulating several flow-induced sound problems including viscous flows around a stationary/vibrating circular cylinder by solving compressible Navier-Stokes equations and gust-cascade interaction noise by solving nonlinear Euler equations. Free of empirical parameters and by exerting suitable construction manners, the influence matrix method is demonstrated most suitable to simulate both the viscous and inviscid flow-induced sound problems. It is then used to study the influence of the inclined angle between an incident gust and a cascade and the slight vibration of the cascade on radiated sound fields for gust-cascade interactions. The inclined angle of the cascade is demonstrated to have a remarkable influence on the upstream and downstream sound pressure distributions. By contrast, the slight vibration is demonstrated to only have a small influence on the radiated sound when the inter-bladephase-angle of vibrating plates is zero.