The Modified Boundary Element Method for Vibration and Sound Radiation Prediction of Fluid-Loaded Structures

Abstract The objective of this study is to modify the conventional Boundary Element Method (BEM) to enable rigorous account of fluid loading. For this purpose the two-level BEM has been developed which allows to split structural and acoustical phases of the problem into two sequential stages. At first step fluid loading is ignored and the in-vacuo normal component of the surface velocity and structural Green’s function are calculated. Then surface pressure distribution is computed from the modified Boundary Integra] Equation with perturbated kernel. Secondly, vibration velocity of fluid-loaded surface is calculated using convolution of the surface pressure and the in-vacuo Green’s function. After that sound pressure is predicted for any control point by Helmholtz formula. The method is applied for volume and planar fluid-loaded radiators as well as to sound scattering by elastic bodies.