title: Vortex sound under the influence of a piecewise porous material on an infinite rigid plane.
abstract: The vortex dynamics and the sound generation by an inviscid vortex in the presence of a finite length porous material on an otherwise rigid plane are studied numerically in the present study in an attempt to understand the sound generation near the surface of a wall lining in a lined duct. The combined effects of the effective fluid density and flow resistance inside the porous material, and the length and thickness of the porous material on the sound generation process are examined in detail. Results obtained demonstrate the sound pressure is longitudinal dipole and show how seriously the above-mentioned parameters are affecting the vortex sound pressure under the influence of the porous material.
authors.affiliation: Department of Building Services Engineering, The Hong Kong Polytechnic University, Hong Kong, P. R. China.
authors.forename: C K
authors.initials: CK
authors.lastname: Lau
authors.forename: S K
authors.initials: SK
authors.lastname: Tang