The generation of an acoustic resonance is modelled for flow past a bluff body in a duct. This paper examines the situation where the rate of vortex shedding is locked to the resonant acoustic frequency. The bluff body has round leading and round trailing edges. The resonant acoustic mode in the duct is predicted via a finite element solution of the Helmholtz equation; good agreement with acoustic frequency is found. The vortex shedding from the plate is predicted using a surface vorticity model of the plate surface and a discrete vortex model of the shed vorticity. The transfer of acoustic power to the sound field from the flow is predicted using Howe's integral. It is found that an imbalance in power transfer to the acoustic field exists during the acoustic cycle as a vortex is formed; the region at the trailing edge of the plate therefore represents an acoustic source.
|Title of host publication||Proceedings of the 9th Australasian Fluid Mechanics Conference|
|Publisher||CCE Conf Management, Faculty of Arts, Univ. of Auckland|
|ISBN (Print)||0868690902, 9780868690902|
|Publication status||Published - 1 Jan 1986|