A closed self-consistent model of a nonequilibrium flow of a mixture of carbon dioxide and
argon behind the front of a plane shock wave is developed. The generalized Chapman–Enskog
method in the three-temperature approach, which takes into account different channels of vibrational
relaxation in a carbon-dioxide molecule, is used. An extended system of Navier–Stokes–Fourier
equations consisting of mass-, momentum-, and energy-conservation equations supplemented by diffusion equations for the mixture components and relaxation equations for vibrational modes of the
CO2 molecule are written. Constitutive relations for the stress tensor, diffusion velocity, heat flux, and
vibrational energy fluxes are obtained. An algorithm for calculating the coefficients of shear and bulk
viscosity, the thermal conductivity of different degrees of freedom, diffusion and thermal diffusion are
developed and implemented. The model is validated by comparing calculated transport coefficients
with experimental data for the viscosity and thermal conductivity of carbon dioxide and argon and for
the binary diffusion coefficient. Good agreement with the experiment is obtained. The dependence of
transport coefficients on the gas temperature, vibrational-mode temperatures, and mixture composition is analyzed. The developed model is ready for use in the numerical simulation of shock waves in
a CO2–Ar mixture