Parallel Large Scale High Accuracy Navier-Stokes Computations on Distributed Memory Clusters

Abstract

We present a highly scalable parallelization of a high-accuracy 3D serial multiblock Navier-Stokes solver. The code solves the full Navier-Stokes equations and is capable of performing large-scale computations for practical configurations in an industrial enviroment. The parallelization strategy is based on the geometrical domain decomposition principle, and on the overlapped communication and computation concept. The important advantage of the strategy is that the suggested type of message-passing ensures a very high scalability of the algorithm from the network point of view, because, on the average, the communication work per processor is not increased if the number of processors is increased. The parallel multiblock-structured Navier-Stokes solver based on the parallel virtual machine (PVM) routines was implemented on 106-processors distributed memory cluster managed by the MOSIX software package. Analysis of the results demonstrated a high level of parallel efficiency (speed up) of the computational algorithm. This allowed the reduction of the execution time for large-scale computations employing 10 million of grid points, from an estimated 46 days on the SGI ORIGIN 2000 computer (in the serial single-user mode) to 5–6 hours on 106-processors cluster. Thus, the parallel multiblock full Navier-Stokes code can be successfully used for large-scale practical aerodynamic simulations of a complete aircraft on millions-points grids on a daily basis, as needed in industry.