Modification of the Chapman-Enskog method as applied to a boundary layer with fast and slow relaxation processes

A modified Chapman-Enskog method is developed for a boundary layer in a chemically reacting mixture of gases with internal degrees of freedom. The analysis is based on an expression relating the characteristic times of elastic and inelastic processes and the characteristic macroscopic time. A system of transport equations is obtained along with formulas for calculating flow terms in the viscous approximation.