In the present monograph, we develop the kinetic theory of transport phenomena and relaxation processes in the flows of reacting gas mixtures and discuss its applications to strongly non-equilibrium conditions. The main attention is focused on the influence of non-equilibrium kinetics on gas dynamics and transport properties. Closed systems of fluid dynamic equations are derived from the kinetic equations in different approaches. We consider the most accurate approach taking into account the state-to-state kinetics in a flow, as well as simplified multi-temperature and one-temperature models based on quasi-stationary distributions. Within these approaches, we propose the algorithms for the calculation of the transport coefficients and rate coefficients of chemical reactions and energy exchanges in non-equilibrium flows; the developed techniques are based on the fundamental kinetic theory principles. The theory is applied to the modeling of non-equilibrium flows behind strong shock waves, in the boundary layer, and in nozzles. The comparison of the results obtained within the frame of different approaches is presented, the advantages of the new state-to-state kinetic model are discussed, and the limits of validity for simplified models are established. The book can be interesting for scientists and graduate students working on physical gas dynamics, aerothermodynamics, heat and mass transfer, non-equilibrium physical-chemical kinetics, and kinetic theory of gases.

A computer program has been developed for one-dimensional nonequilibrium reacting gas flow. The program is written in Fortran IV and is compatible with the IBM 7044/7094 direct coupled digital computer system at Wright-Patterson Air Force Base, Ohio. In addition to nonequilibrium chemistry, the program includes nonequilibrium vibrational and electronic energy relaxation and coupling effects between these energy modes and the chemistry. The formulation is based on a one-dimensional flow matching either a prescribed pressure or area variation along a streamtube. Thermodynamic properties are computed by assuming an ideal gas mixture and the equilibration of translational and rotational temperatures. The internal energy modes, rotation, vibration, and electronic excitation, are considered uncoupled; and a rigid rotator, cut off simple harmonic oscillator, independent of the electronic state, is assumed. Excitation of vibrational and electronic energies are treated similarly with terms which account for relaxation and chemical reactions. The effects of nonequilibrium vibrational and electronic states on chemical rates are included in the coupling analysis. The vibrational relaxation time constants were obtained from the Millikan and White data while the electronic relaxation time constants were determined for nitrogen from an analysis of existing shock tube radiation measurements. The computer program was used to solve for the nonequilibrium flow in a hypersonic nozzle and for eight streamlines in the inviscid flow field over a spherically blunted nine-degree semiapex angle cone at zero angle of attack. (Author).

7.1 Introduction -- 7.2 Rotational Energy Exchange Models -- 7.2.1 Constant Collision Number -- 7.2.2 The Parker Model -- 7.2.3 Variable Probability Exchange Model of Boyd -- 7.2.4 Nonequilibrium Direction Dependent Model -- 7.2.5 Model Results -- 7.3 Vibrational Energy Exchange Models -- 7.3.1 Constant Collision Number -- 7.3.2 The Millikan-White Model -- 7.3.3 Quantized Treatment for Vibration -- 7.3.4 Model Results -- 7.4 Dissociation Chemical Reactions -- 7.4.1 Total Collision Energy Model -- 7.4.2 Redistribution of Energy Following a Dissociation Reaction -- 7.4.3 Vibrationally Favored Dissociation Model -- 7.5 General Chemical Reactions -- 7.5.1 Reaction Rates and Equilibrium Constant -- 7.5.2 Backward Reaction Rates in DSMC -- 7.5.3 Three-Body Recombination Reactions -- 7.5.4 Post-Reaction Energy Redistribution and General Implementation -- 7.5.5 DSMC Solutions for Reacting Flows -- 7.6 Summary -- Appendix A: Generating Particle Properties -- Appendix B: Collisional Quantities -- Appendix C: Determining Post-Collision Velocities -- Appendix D: Macroscopic Properties -- Appendix E: Common Integrals -- References -- Index

Chemical Kinetics relates to the rates of chemical reactions and factors such as concentration and temperature, which affects the rates of chemical reactions. Such studies are important in providing essential evidence as to the mechanisms of chemical processes. The book is designed to help the reader, particularly students and researchers of physical science, understand the chemical kinetics mechanics and chemical reactions. The selection of topics addressed and the examples, tables and graphs used to illustrate them are governed, to a large extent, by the fact that this book is aimed primarily at physical science (mainly chemistry) technologists. Undoubtedly, this book contains "must read" materials for students, engineers, and researchers working in the chemistry and chemical kinetics area. This book provides valuable insight into the mechanisms and chemical reactions. It is written in concise, self-explanatory and informative manner by a world class scientists in the field.

In high energy gas flows, at high velocities and high temperatures, physical and chemical processes such as molecular vibrational excitation, dissociation, ionisation or various reactions take place and deeply influence the structure of the flows. The characteristic times of these processes have the same order of magnitude as aerodynamic characteristic times, so that these reactive media are generally in thermodynamic and chemical non-equilibrium. This book presents a general introductory study of these media. In the first part their fundamental statistical aspects are described, starting from their discrete structure and taking into account the interactions between elementary particles: transport phenomena, relaxation and kinetics as well as their coupling are analysed and illustrated by many examples. The second part deals with the macroscopic re-entry bodies. Finally, the experimental aspects of these flows, their simulations in shock tubes and shock tunnels are described, as well as their application, particularly in the aerospatial domain. This book is intended for students that have acquired a basic knowledge in thermodynamics, statistical physics and fluid mechanics. It will also be of interest to engineers in research and industry, in particular in the aerospace industry, and more generally to all researchers trying to simulate and calculate complex reactive flows.

Introduces advanced mathematical tools for the modeling, simulation, and analysis of chemical non-equilibrium phenomena in combustion and flows, following a detailed explanation of the basics of thermodynamics and chemical kinetics of reactive mixtures. Researchers, practitioners, lecturers, and graduate students will find this work valuable.