A MULTIPOLE DIRECT AND INDIRECT BEM FOR 2D CAVITY FLOW AT LOW-REYNOLDS-NUMBER

A multipolar methodology is applied to the boundary element method (di rect and indirect formulation) in order to solve bidimentional Stokes cavity flow. The algorithm based on mixed multipolar expansion and num erical integration is applied not only for very large problems but als o for intermediate and small problems. In comparison with the direct f ormulation, the indirect formulation is more stable with the iterative solvers, and does not need to be preconditioned to obtain a fast conv ergence. A good result in memory saving and computing time is obtained that enables us to run huge examples which are prohibitive for tradit ional BEM implementations. (C) 1997 Elsevier Science Ltd.