We compare the Immersed Interface Method (IIM) with the Extended Finite
Element Method (X-FEM) for elliptic equations with singular sources and
discontinuous coefficients. The IIM has been compared favorably with a number of
other competing methods. These methods are of particular interest because they
allow for the solution of elliptic equations with internal boundaries on nonconforming
meshes. In the context of moving interface problems, the emphasis in this paper is
placed on accuracy of solutions and their normal derivatives on the interface. These
methods are briefly described and the results for benchmark problems are
compared.
Keywords
cartesian grids, discontinuous coefficient, elliptic
equation, extended finite element method, finite difference
methods, finite element methods, immersed interface method,
immersed boundary method, irregular domain, level set
methods, singular source term