ABSTRACT
There are a number of ows, mainly in ‰elds with heat and mass transfer, where it is observed that there are disagreements between experimental and corresponding theoretical results. Thermophoresis is such a ‰eld (e.g., Brenner, 2005), and shock waves with their strong temperature and density gradients are another (e.g., Greenshields and Reese, 2007), to just mention two of the ows related to the subject treated in this chapter. This treatment relates to gas ows through microchannels as they occur in microelectromechanical systems (MEMS). Flows of this kind are also not predicted correctly by the basic equations of uid mechanics because they are used these days.
