Rarefied gas dynamics is important in the semiconductor fabrication and almost any process that involves high vacuum, as well as in the
development of the high-vacuum equipment itself.
As the demand for the high performance products in these industries has increased, the numerical computation of rarefied gas dynamics is crucial.
Any equation in the governing equations and the numerical algorithms has its generality only in the dimensionless form.
This paper presents the nondimensionalization procedure for the numerical computation of rarefied gas dynamics with the Boltzmann equation
by the Direct Simulation Monte Carlo (DSMC) method. The Boltzmann equation is nondimensionalized with the Froude number according to the method proposed by Hellums and Churchill.
