functionKnudsenNumber

Returns Knudsen number

Extends from Modelica.Icons.Function (Icon for functions).

Information

Defined to be the ratio of the length scale between interactions divied by the characteristic length scale of the problem

  • Kn = L_ms/L_char

If Kn is not << 1 then continuum theory breaks down and the calculus assumption to derive dT/dx as the lim dx -> 0 is not valid.

This limit may be reached in micro and nano-scale systems where L_char becomes small as well as in problems involving rarefied gas where L+ms becomes large.

Inputs

TypeNameDefaultDescription
SI.LengthL_msDistance between energy carrier interactions
SI.LengthL_charLength scale that characterizes the problem

Outputs

TypeNameDefaultDescription
Units.NonDimKnJakob number