Gaseous mixtures in vacuum systems and microfluidics

Abstract

In vacuum technology, one deals with gaseous mixtures more frequently than with a single gas, but the information about transport phenomena in mixtures published in the open literature is very poor. Moreover, methods to modelmixture flows are more complicated than those for single gas. The aim of this work is to review general approaches to modeling mass, heat, and momentum transfer through gaseous mixtures over the whole range of gas rarefaction. This review is written in an easy, accessible manner avoiding hard mathematical derivations, though an extensive list of references is provided for readers wishing to find more details about the field. Results for some classical problems such as velocity slip and temperature jump coefficients, Poiseuille flow,Couette flow, and heat transfer for gaseous mixtures are presented in graphical form. A comparison of these results with those corresponding to a single gas is presented, which shows the peculiarities of the transport phenomena in mixtures and gives us an idea how to model mixture flows in vacuum systems and microfluidics.