On the behavior of the volume viscosity of atom-molecule mixtures.

The behavior of the volume viscosity in atom-molecule gas mixtures is investigated in the framework of the first-order Enskog–Chapman expansion when the internal-energy relaxation cross section for atom-molecule collisions is small compared to that for molecule-molecule collisions. Two phenomena are analyzed: first, the sensitivity of the volume viscosity to this particular cross section allows the volume viscosity of the atom-molecule mixture to be significantly larger than that of the pure molecular gas; second, when this cross section is set to zero, the volume viscosity becomes discontinuous at the pure-atom limit.© 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]