Parallel unstructured mesh CFD codes: a role for recursive clustering techniques in mesh decomposition

In principle, unstructured mesh CFD codes can be parallelised using a mesh decomposition approach similar to structured mesh codes. However, for unstructured codes the mesh structure is problem dependent and algorithms for automatically decomposing the mesh onto the processors are required. An algorithm based upon a recursive clustering technique, for decomposing meshes into an arbitrary number of sub-domains with a nearest neighbour connectivity for a specified processor topology, is used as a preprocessor to a parallel unstructured mesh CFD code. Parallel performance shows efficiency levels equivalent to structured mesh codes using similar solution procedures.