PARALLEL DOMAIN DECOMPOSITION APPROACH FOR LARGE-SCALE THREE-DIMENSIONAL BOUNDARY-ELEMENT MODELS IN LINEAR AND NONLINEAR HEAT CONDUCTION

Abstract

The boundary-element method (BEM) requires only a surface mesh to solve linear and nonlinear heat conduction problems, but the resulting matrix is fully populated. This poses serious challenges for large-scale three-dimensional problems due to storage requirements and iterative solution of a large set of nonsymmetric equations. In this article, we develop a domain decomposition, or artificial subsectioning technique, along with a region-by-region iteration algorithm particularly tailored for parallel computation to address these issues. A coarse-surface grid solution coupled with an efficient physically based procedure provides an effective initial guess for a fine-surface grid model. The process converges very efficiently, offering substantial savings in memory. The iterative domain decomposition technique is ideally suited for parallel computation. We discuss its implementation on a modest Windows XP Pentium P4 PC cluster running under MPI with MPI2 extensions. Results from three-dimensional BEM heat conduction models including models of upwards of 85,000 nodes arising form an intricate film-cooled vane. We demonstrate that the BEM can readily be applied to solve large-scale linear and nonlinear heat conduction problems and that such solutions can be readily undertaken on modest PC clusters.