On the effect of the boundary conditions and the collision model on rarefied gas flows

Abstract

In this work, the effect of the gas-surface interaction law and of the intermolecular collision model is examined by solving, using the DSMC method, the heat transfer problem between parallel plates and the non-isothermal Poiseuille flow problem. In the former one the Cercignani-Lampis model is applied to analyze the influence of the gas-surface interaction parameters, while in the latter one a comparison between the results obtained by implementing the Hard Sphere, Variable Hard Sphere, Variable Soft Sphere and Maxwellian models is performed. Calculations have been carried out for several values of the Knudsen number, temperature ratio and Froude number. A comparison between the DSMC and the corresponding discrete velocity results yields very good agreement between the two approaches. Finally, the convergence behavior of a Bernoulli trials based scheme, which allows the use of a smaller number of particles per cell, and the No Time Counter are compared for different sampling sequences. © 2011 American Institute of Physics.