Implementation of a hypersonic rarefied flow particle simulation on the connection machine

A very efficient direct particle simulation algorithm for hypersonic rarefied flows is presented and its implementation on a Connection Machine is described. The implementation is capable of simulating up to 4 x 106 hard sphere diatomic molecules using 64k processors with a performance better than that of a similar, fully vectorized implementation using a single processor of the Cray 2. Results from flow calculations are presented to demonstrate both the validity of the implementation and the range afforded by the method in solving hypersonic rarefied flow problems. Finally, a breakdown of the calculation time is given to identify a bottleneck which must be resolved for further improvement in performance.