Author(s)

M. Hribersek and L. Skerget

Abstract

The paper presents new development of ILU based preconditioned for solving large sparse systems of linear equations arising from Boundary-Domain Integral Method (BDIM) as a Navier-Stokes equations solver. Level based fill-in is intro- duced to incomplete LU decomposition of BDIM based system matrices. Special attention is focused on initial formation of level ILU pattern for preconditioners and on effective use of this pattern in outer non-linear loop of BDIM algorithm. Computed test examples show that adding only one level of fill-in already sig- nificantly improves convergence of iterative solvers together with large savings in CPU time requirements, although additional levels have to be added in some extreme cases. 2 Background of the problem Iterative solution of large

Keywords