Vectorized Monte Carlo molecular aerodynamics simulation of the Rayleigh problem

A fully vectorized version of a one-dimensional Monte Carlo algorithm applied to molecular aerodynamics is presented. The algorithm is applied to the Rayleigh problem, an impulsively accelerated, heated flat plate, and is implemented on the CYBER 205. Issues relating to the details of vectorization, including the use of bit addressability, the maintaining of long vector lengths, and vector gather/scatter use, are discussed. Speedup factors due to vectorization in the range of 5 to 18 are reported, depending on problem parameters. The results indicate that under certain circumstances, the problem performs well on vector architectures