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Strategies for parallelizing a Navier‐Stokes code on the intel touchstone machines
Author(s) -
Häuser Jochem,
Williams Roy
Publication year - 1992
Publication title -
international journal for numerical methods in fluids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 112
eISSN - 1097-0363
pISSN - 0271-2091
DOI - 10.1002/fld.1650150105
Subject(s) - computer science , parallel computing , mimd , grid , computation , computational science , block (permutation group theory) , massively parallel , load balancing (electrical power) , code (set theory) , topology (electrical circuits) , algorithm , mathematics , geometry , set (abstract data type) , combinatorics , programming language
The purpose of this paper is to predict the efficiency of the Navier‐Stokes code NSS* which will run on an MIMD architecture parallel machine. Computations are performed using a three‐dimensional overlapping structured multiblock grid. Each processor works with some of these blocks and exchanges data across the boundaries of the blocks. The efficiency of such a code depends on the number of grid points per processor, the amount of computation per grid point and the amount of communication per boundary point. In this paper we estimate these quantities for NSS* and present measurements of communication times for two parallel machines, the Intel Touchstone Delta machine and an Intel iPSC/860 machine, consisting of 520 and 64 Intel i860 processors respectively. The peak performance of the Delta machine is 32 Gflop. Secondly it is shown how, starting from a seven‐block grid of about 5000 000 points for the Hermes space plane, a mesh of 512 equally sized blocks is constructed retaining the original topology. This example demonstrates that multiblock grids provide sufficient control over both the number and size of blocks. Therefore it will be possible to simulate realistic configurations on massively parallel systems with a specified number of processors while achieving good quality load balancing.