Validity of Continuum Assumption?

Richard

Hi --

I am aware that the mean free path (MFP) of molecules is the limiting factor in considering a fluid to be a continuum. However, most of the references to MFP calculations point to ideal gas analysis. Any suggestions on finding some representative values of the MFP for liquid water over a range of (P,T) data?

I am evaluating the appropriateness of some recent attempts to numerically model "wedge flow" in some crevices on the scale of 10-50 nm using non-modified NS descriptions. Since the molecular size of H2O is about 0.5 nm, this seems (at best) to be in the granular flow regime.

Thanks in advance! Richard