Load balancing for spatial-grid-based parallel numeric simulations on clusters of SMPs -- a case study from an industrial CFD simulation. Load distribution is an essential factor to parallel efficiency of numerical simulations that are based on spatial grids, especially on clusters of symmetric multiprocessors (SMPs). This paper presents a method of mapping spatial grid nodes to processors that combines 2 load balancing methodologies, graph partitioning and graph matching, to achieve maximum parallel efficiency on SMP clusters. The method has been successfully applied to load distribution in a parallel Computational Fluid Dynamics (CFD) simulation code named TRACE. Test runs on the SR8000 prove the effectiveness of the method.