Direct simulation-techniques for the Boltzmann equation. (English) Zbl 0593.76086

DFVLR Forschungsber. DFVLR-FB-13, 67 p. (1985).
Summary: Several test cases serve for a comparison of the efficiency of the molecular dynamics method and the direct simulation Monte Carlo techniques for computing solutions of the Boltzmann equation. Both methods yield equally good results for simple flowfields. However, only the molecular dynamics method is capable of simulating the generation and separation of vortices, the DSMC yields wrong results for this problem. The reason for this is found in the statistical assumptions underlying the evaluation of the collision term in the DSMC. These lead to the non- conservation of angular momentum for the interaction of particles, which in turn results in a wrong representation of the vorticity field.


76P05 Rarefied gas flows, Boltzmann equation in fluid mechanics
76M99 Basic methods in fluid mechanics