Automatic load balancing in parallel direct simulation methods

Abstract

Performing Direct Simulation Monte Carlo (DSMC) calculations on parallel processors may result in a strongly unbalanced distribution of work. This situation affects the performances leading to very low speedups. A method that makes use of adaptive domain decomposition to dynamically distribute the computational work load is presented. The method had been implemented on a Transputer System with up to 8 processors (20 MHz Inmos T800), using the FORTRAN version of Parasoft Express Library for parallel computers. The problems studied were hypersonic flows of a chemically reacting gas in a two-dimensional domain. The adaptive decomposition method worked well in uniformly distributing the computational work over an arbitrary number of processors and reduced the average execution time by over 45% in certain cases.<>