introduction to reactive gas dynamics apr 2009

[...]... grateful to J.G Meolans for his direct contribution to various theoretical subjects exposed here, to D Zeitoun for the numerical processing of various problems, and also to L.Z Dumitrescu for his participation in many experiments Thanks are also owed to N Belouaggadia for her contribution to the editing of Chapters 5 and 6 The suggestions and corrections brought to the initial text by G Duffa and J.C Lengrand... (1.32) Two unknowns still need to be determined in order to find the directions of the velocities after collision, for example the angles χ (deviation angle) and α (azimuth angle) (Fig 1), which completely determine the relative directions of g and g To do this, it is necessary to analyse the trajectory of the particles in the interaction zone, and therefore to take into account the forces acting on... theory of gases’ As for applications, impressive strides have been made, especially in the domain of aeronautics and astronautics These applications are indeed at the origin of the increased interest in highenthalpy gas flows, related to supersonic and hypersonic flight as well as to laser and plasma flows In these flows, the important energies involved give rise to high temperatures and then to chemical... and these contributors have to be thanked for the significant improvements brought to this text; furthermore, without the (friendly) insistence of G Duffa, this book would probably never have been written Many thanks are also due to G de Terlikowska for having read the complete manuscript and bringing substantial improvements to it Finally, the author expresses his deep gratitude to B Shizgal for reading... vibration modes (0 or 1) ONE Statistical Description and Evolution of Reactive Gas Systems 1.1 Introduction The macroscopic representation of gaseous media is based on their discrete structure and is deduced from the behaviour of individual particles such as molecules, atoms, and so on1−7 A statistical description is therefore necessary in order to explain the properties and the evolution of these media, particularly... represents the total momentum flux: it is a symmetrical second-order tensor corresponding to the ‘internal’ forces of the medium 10 CHAPTER 1 REACTIVE GAS SYSTEMS (Newton’s law), due to the momentum exchanges between the mean streamlines of the flow As is well known, the diagonal terms represent the stresses normal to the considered surface element (normal N), and the others the tangential stresses Thus,... n = 20, ; Appendix 4.5) From a macroscopic point of view, it seems simpler to restrict ourselves to the three equations (1.26) for well-defined physical situations and to try to obtain information on the distribution function so as to close the system of equations (1.26) (Chapters 2 and 3) Moreover, it is often important to know the evolution of the ‘intermediate’ quantities, such as the species concentrations... domain of reactive flows The author is grateful to his coworkers, essentially students, who, while preparing their theses, have contributed to the progress and/or the investigation of numerous topics presented herein All cannot be mentioned here, but their contribution can be appreciated in the extensive citations to their work in the bibliographic references The author is particularly grateful to J.G... transport properties are determined for pure gases as well as for mixtures, taking into account external influences; these solutions correspond to a linearized non-equilibrium of zero-order solutions Chapter 5 is also devoted to properties of the first-order solutions (transport and relaxation) in media considered in non-equilibrium at zero order, taking into account also the possible interaction between... Index 405 This page intentionally left blank Introduction For more than a century, the properties of gaseous flows have been systematically analysed, both for the basic knowledge itself and for practical applications This endeavour can be viewed from two aspects: firstly, the analysis of the elementary or microscopic phenomena of gaseous media, belonging to ‘atomic and molecular physics’; and secondly, .