A BEM/GA APPROACH TO SHAPE OPTIMIZATION OF 3-D ACOUSTIC SCATTERING BODIES

摘要

Shape optimization of acoustic scattering bodies is carried out using genetic algorithmsrn(GA) coupled to a boundary element method for exterior acoustics. The BEMrnformulation relies on a modified Burton-Miller algorithm to resolve exterior acousticsrnand to address the uniqueness issue of the representation problem associated with thernHelmholtz integral equation at the eigenvalues of the associated interior problem. Thernparticular problem of interest considers an incident wave approaching an axisymmetricrnshaped body. The objective is to arrive at a geometric configuration that minimizes thernacoustic intensity captured by a receiver located at a distance from the scattering body. Inrnparticular, the acoustic intensity is required to be minimum as measured proportional tornthe integral of the product of the potential and its complex conjugate over a volume ofrnspace which models the receiver. This is opposed to the more traditional measure of thernpotential at a single point in space.