Sound field alteration through cavity shape design using a Wavelet-Galerkin Method

Abstract

The general problem of internal sound field prediction along with the manipulation of the cavity boundary shape to alter the sound pressure distribution is dealt with in this paper. Owing to the compactly supported orthogonal property of the wavelet and its extraordinary fitting capability, Daubechies wavelet scaling function is used as a global basis function to expand the unknown sound pressure under the general Galerkin framework. The proposed formulation is shown to offer high accuracy on the numerical calculation of the sound pressure field with the use of a remarkably small number of messing points. A genetic based shape optimization algorithm is proposed and demonstrated. As an example, an enclosure with an inner rigid acoustic screen is investigated. By optimizing the shape of the screen, the sound pressure level within a chosen area is successfully reduced. Results show the remarkable potentials of the proposed approach as a topology optimal tool for the general inner sound field problems.