Investigation of acoustic radiation from a sphere pulsating on the free surface using a boundary element approach

In this study a boundary element method (BEM) is applied to investigate acoustic radiation from a sphere pulsating on the free surface of infinitely deep water. Effect of the free surface is introduced by employing a half-space Green’s function. A modified version of the Helmholtz integral equation (HIE) is used to calculate acoustic radiation from the sphere pulsating on the free surface. Free-terms of the HIE are calculated using two different forms of integrals and “dummy” boundary elements. To demonstrate applicability of the method presented, calculated acoustic pressures are compared with those by finite element (FE) method and analytical calculations. Moreover, effects of submergence depth and vibration frequency are investigated. The calculations show that there is a very good agreement between BE, FE results and analytical solutions. Also, it is observed that submergence depth and vibration frequency have significant effects on the radiated pressure magnitude and the pressure field pattern.