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Title: Reaction and internal energy relaxation rates in viscous thermochemically non-equilibrium gas flows

In the present paper, reaction and energy relaxation rates as well as the normal stress are studied for viscous gas flows with vibrational and chemical non-equilibrium. Using the modified Chapman-Enskog method, multi-temperature models based on the Treanor and Boltzmann vibrational distributions are developed for the general case taking into account all kinds of vibrational energy transitions, exchange reactions, dissociation, and recombination. Integral equations specifying the first-order corrections to the normal mean stress and reaction rates are derived, as well as approximate systems of linear equations for their numerical computation. Generalized thermodynamic driving forces associated with all non-equilibrium processes are introduced. It is shown that normal stresses and rates of non-equilibrium processes can be expressed in terms of the same driving forces; the symmetry of kinetic coefficients in these expressions is proven. The developed general model is applied to a particular case of a pure N{sub 2} viscous flow with slow VT relaxation. Normal stress and rates of vibrational relaxation are studied for various ratios of vibrational and translational temperatures. The cross effects between different vibrational transitions in viscous flows are evaluated, along with the influence of anharmonicity and flow compressibility on the first-order corrections to the relaxation rate. Limits ofmore » validity for the widely used Landau–Teller model of vibrational relaxation are indicated.« less
Authors:
;  [1]
  1. Department of Mathematics and Mechanics, Saint Petersburg State University, Universitetskiy pr., 28, Saint Petersburg 198504 (Russian Federation)
Publication Date:
OSTI Identifier:
22403210
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Fluids (1994); Journal Volume: 27; Journal Issue: 1; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; APPROXIMATIONS; BOLTZMANN STATISTICS; COMPRESSIBILITY; CORRECTIONS; DISSOCIATION; EXCHANGE INTERACTIONS; GAS FLOW; INTEGRAL EQUATIONS; REACTION KINETICS; RECOMBINATION; RELAXATION; STRESSES; THERMOCHEMICAL PROCESSES; THERMODYNAMICS; VISCOUS FLOW