A new hybrid method between equivalent source method and boundary element method for modeling diffraction

Abstract

The Equivalent Source Method (ESM) allows to model the acoustical radiation of an object with a set of monopole sources inside the object. This method efficiently describes acoustical radiation of an object with smooth surface, but is not performant for addressing diffraction induced by sharp edge. In this study, we use the simple source formulation to establish ESM as an integral formulation. In this form, ESM belong to the Boundary Element Method (BEM) family, with an implicit mesh. Therefore, we propose an alternative method similar to ESM with sources on the surface object, as the singularities can now be handled with the integral formulation. This new method is more performant than ESM for modeling diffraction, and is easier to implement than standard BEM based on Gauss Quadrature while it still takes advantage of the ESM implicit mesh. Comparisons of this hybrid method with ESM and standard BEM approaches show that the developed method is a good compromise between the two other approaches: the new method is more accurate than BEM, but less than ESM for a smooth object; while it is equivalent to BEM and more accurate than ESM for an edgy object. Work Funded by AMIDEX foundation.