Knudsen Number

Written by Jerry Ratzlaff on . Posted in Dimensionless Numbers

Knudsen number, abbreviated as Kn, is a dimensionless number that is used in fluid dynamics to determine what type of analysis should be used to model an object moving through a fluid.  It is defined as the ratio of the molecular mean free path length to a representative physical length scale.  This calculation determines the Knudsen number, the length or the lambda value based on your inputs.

 

Knudsen number calculator

formulas  that use Knudsen Number

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

Where:

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

\(\large{ l }\) = length

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

 

   

 

 

 

Tags: Equations for Fluid Calculators