Numerical simulation of rarefied gas flow through a slit
Abstract
Two different approaches, the finitedifference method coupled with the discreteordinate method (FDDO), and the directsimulation Monte Carlo (DSMC) method, are used in the analysis of the flow of a rarefied gas from one reservoir to another through a twodimensional slit. The cases considered are for hard vacuum downstream pressure, finite pressure ratios, and isobaric pressure with thermal diffusion, which are not well established in spite of the simplicity of the flow field. In the FDDO analysis, by employing the discreteordinate method, the Boltzmann equation simplified by a model collision integral is transformed to a set of partial differential equations which are continuous in physical space but are point functions in molecular velocity space. The set of partial differential equations are solved by means of a finitedifference approximation. In the DSMC analysis, three kinds of collision sampling techniques, the time counter (TC) method, the null collision (NC) method, and the no time counter (NTC) method, are used.
 Publication:

AIAA and ASME, 5th Joint Thermophysics and Heat Transfer Conference
 Pub Date:
 June 1990
 Bibcode:
 1990jtht.confS....K
 Keywords:

 Channel Flow;
 Computational Fluid Dynamics;
 Finite Difference Theory;
 Monte Carlo Method;
 Rarefied Gas Dynamics;
 Slits;
 Boltzmann Transport Equation;
 Partial Differential Equations;
 Pressure Gradients;
 Reservoirs;
 Fluid Mechanics and Heat Transfer