Knudsen number (For a Boltzmann gas)

Description

The Knudsen number (Kn) is a dimensionless number defined as the ratio of the molecular mean free path length to a representative physical length scale. This length scale could be, for example, the radius of the body in a fluid. For a Boltzmann gas Knudsen number is depended on the thermodynamic temperature, the particle hard shell diameter and the total pressure.

Related formulas

Variables

KnKnudsen number (dimensionless)
kBBoltzmann constant
TThe thermodynamic temperature (K)
πpi
dThe particle hard shell diameter (m)
PThe total pressure, (Pa)
LThe representative physical length scale (m)