Abstract: In an improvement over conventional finite element techniques, a prolate spheroidal infinite element is used for the modeling of acoustic fields in exterior, fluid-filled domains surrounding a structure. This prolate infinite element is based on a multipole expansion that describes, to arbitrary accuracy, any scattered and/or radiated field exterior to a prolate spheroid of any eccentricity. The prolate infinite elment is readily incorporated in any structural or acoustical finite element code. Structural acoustic modeling with the element is several orders of magnitude faster than modeling, at comparable accuracy, with the well-known and widely used boundary element method, at least for large-scale problems involving tens of thousands of degrees of freedom.

Abstract: In an improvement over conventional finite element techniques, an oblate spheroidal infinite element is used for the modeling of acoustic fields in exterior, fluid-filled domains surrounding a structure. This oblate infinite element is based on a multipole expansion that describes, to arbitrary accuracy, any scattered and/or radiated field exterior to an oblate spheroid of any eccentricity. The oblate infinite elment is readily incorporated in any structural or acoustical finite element code.