A Galerkin projection technique for the evaluation of potential derivatives on a smooth boundary in 2D BEM

A new simple and general technique for potential gradient recovery along the boundary in two-dimensional BEM is introduced and studied numerically. This technique is based on generalized Galerkin projections, and its basic formulation corresponds to a least-squares method. In preliminary numerical tests for Dirichlet and Neumann problems on smooth boundaries, this technique shows excellent accuracy. The normal flux is evaluated more accurately than direct BEM results, and the tangential flux values are calculated more accurately than with a local averaging technique.