Classical transport collision integrals for a Lennard-Jones like phenomenological model potential

A general purpose analytical expression for collision integrals, up to (l,s) = (4, 4), of non-reactive interactions between heavy particles is proposed. The expression has been obtained from the classical cross section calculation for a model potential depending on few parameters, related directly to physical properties of the interacting particles. The fitting function has been verified in the temperature range 10^2 to 10^5 K making these collision integrals suitable for Chapman-Enskog calculations of complex mixtures in high enthalpy fluid dynamics. Parameter values for all the relevant interactions in 11 species air model have been reported.