On a novel application of the Helmholtz integral in the development of a virtual sonar

A novel application of the Helmholtz integral is presented in the developme nt of a virtual sonar. Given total pressure and normal velocity information over the surface of a structure which has been excited both by incident fi elds as well as interior noise sources, when the Helmholtz integral is eval uated at field points located within the surface of the structure (using th e free-space Green's function characteristic of the exterior medium), only the incident field remains. Therefore, it is possible to remove the effects of both scattering (due to incident excitation) and radiation (due to inte rior noise sources) throughout a ''virtual'' volumetric sonar array project ed within the structure. This approach will be discussed and demonstrated u sing numerical results based on finite element simulations. (C) 2000 Acoust ical Society of America. [S0001-4966(00)00112-0].