Physical-chemical gas-dynamics: challenges and solutions

Yu.E. Gorbachev 1 , E.G. Kolesnichenko 2
1Research Department, Coddan Technologies LLC, 197342 St. Petersburg, Russia
2Gas Kinetics Lab, Moscow State University, Institute for Mechanics, 117192 Moscow, Russia

Abstract: One of the main problems of the non-equilibrium physical-chemical gas-dynamics
is considered: derivation of gas-dynamics equations for reactive gas mixtures. By non-
equilibrium effects we mean all kinds of effects caused by deviation of the distribution
function from its quasi-equilibrium value. The method which is used to obtain the normal
solution for the generalized Boltzmann equation is discussed. As opposed to the tradi-
tional approach, it permits a description of experimentally observed pressure dependence
of the reaction rates (low- and high-pressure limits) and to generalize the theory of ther-
mal dissociation for the arbitrary reaction case and for spatially inhomogeneous systems.
Conclusions concerning the necessity of revising the traditional approach to the chemical
reaction description and of developing the non-equilibrium chemistry are argued. In the
framework of the non-equilibrium chemistry, chemical reactions are no longer independent
of each other (Guldberg and Waage law is not applicable under the non-equilibrium condi-
tions) and corresponding reaction rates are functions of the reacting mixture composition.
Exact expressions for reaction and relaxation rates for the cut-off harmonic oscillator model
are obtained. Only the case of hard potentials in Grad’s meaning is considered, while soft
potentials remain an issue.

Keywords: Physical-chemical gas-dynamics, kinetic theory, Boltzmann equation, reactive
mixture, transport equations, non-equilibrium effects, reaction rates
Mathematics Subject Classification: 76A99, 82B40
PACS: 05.20.Dd, 05.60 +w, 51.10+y, 82.20. Mj


Scroll to Top