On the fast matrix multiplication in the boundary element method by panel clustering

Summary The boundary element method (BEM) leads to a system of linear equations with a full matrix, while FEM yields sparse matrices. This fact seems to require much computational work for the definition of the matrix, for the solution of the system, and, in particular, for the matrix-vector multiplication, which always occurs as an elementary. In this paper a method for the approximate matrix-vector multiplication is described which requires much less arithmetical work. In addition, the storage requirements are strongly reduced.This paper reports results of a research project supported by the DFG (Schwerpunktprogramm Finite Approximationen in der Strömungsmechanik