FETI domain decomposition methods for scalar advection-diffusion problems

In this paper, we show that iterative substructuring methods of finite elem ent tearing and interconnecting type can be successfully employed for the s olution of linear systems arising from the finite element approximation of scalar advection-diffusion problems. Using similar ideas as those of a rece ntly developed Neumann-Neumann method, we propose a one-level algorithm and a class of two-level algorithms, obtained by suitably modifying the local problems on the subdomains. We present some numerical results for some sign ificant test cases. Our methods appear to be optimal for flows without clos ed streamlines and possibly very small values of the viscosity. They also s how very good performances for rotating flows and moderate Reynolds numbers . Therefore, the algorithms proposed appear to be well-suited for many conv ection-dominated problems of practical interest. (C) 2001 Elsevier Science B.V. rights reserved.