Galerkin Versions of Nonsingular Trefftz Method Derived from Variational Formulations for 2D Laplace Problem

In the paper, application of the Trefftz complete functions and Kupradze functions in two variational formula-tions is compared. They are applied in the original formulation and in the inverse one to the solution of boundary value problems of two-dimensional Laplace’s equation. In these formulations, both solution and weighting functions are assumed to be of the same type, either the Trefftz function or the Kupradze function. Thus Galerkin versions of the methods are considered. All methods lead to the BEM and they are nonsingular. The relationship between the groups of methods of the original and inverse formulations is noticed. Numerical experiments are conducted for the Motz’s problem. The accuracy and simplicity of the methods are discussed. All methods give comparable results. Since they are nonsingular, they may be successfully applied to solving boundary problems