Knudsen Number

Written by Jerry Ratzlaff on . Posted in Dimensionless Numbers

Knudsen number ( \(Kn\) ) (dimensionless number) is defined as the ratio of the molecular mean free path length to a representative physical length scale.

Knudsen Number FORMULA

:(Kn

\(\large{ Kn = \frac{ \lambda }{ l }  }\)

Where:

\(\large{ Kn }\) = Knudsen number

\(\large{  l }\) = length

\(\large{ \lambda }\)  (Greek symbol lambda) = mean free path

Solve for:

\(\large{ \lambda =  Knl  }\)

\(\large{ l = \frac{ \lambda }{ Kn }  }\)