Molecular Physics and Hypersonic Flows bridges the gap between the fluid dynamics and molecular physics communities, emphasizing the role played by elementary processes in hypersonic flows. In particular, the work is primarily dedicated to filling the gap between microscopic and macroscopic treatments of the source terms to be inserted in the fluid dynamics codes. The first part of the book describes the molecular dynamics of elementary processes both in the gas phase and in the interaction with surfaces by using quantum mechanical and phenomenological approaches. A second group of contributions describes thermodynamics and transport properties of air components, with special attention to the transport of internal energy. A series of papers is devoted to the experimental and theoretical study of the flow of partially ionized gases. Subsequent contributions treat modern computational techniques for 3-D hypersonic flow. Non-equilibrium vibrational kinetics are then described, together with the coupling of vibration-dissociation processes as they affect hypersonic flows. Special emphasis is given to the interfacing of non-equilibrium models with computational fluid dynamics methods. Finally, the last part of the book deals with the application of direct Monte Carlo methods in describing rarefied flows.

One of the most challenging problems of modern engineering is undoubtedly the prediction of hypersonic flows around space vehicles in reentry conditions. Indeed, the difficulties are numerous: first of all, these flows are very difficult to model, since very complex physical and chemical phenomena take place during the reentry phase; secondly, temperature, velocity and enthalpy are very high and densities are very low, making the reentry process very difficult to reproduce in ground-based experiments. The past three decades have seen important efforts in computational fluid dynam ics relying on the use of supercomputers to simulate these very complicated flows. The numerical simulation based on imperfect models and methods which were es sentially designed for transonic and supersonic flows has still a long way to go in order to be able to predict these hypersonic reentry flows very accurately. This situation has motivated very strong international cooperative efforts with, as the most visible consequences, the EuropelUnited States Short Courses on Hy personics, which were held in Paris, in 1987 [1,2], Colorado Springs in 1989 [3], and Aachen in 1990 [3]. The workshop on Hypersonics whose results are presented and analysed in these volumes is also a direct consequence of this international cooperation. This scien tific event was an initiative of P. Perrier, Head of the Theoretical Aerodynamics Department of DASSAULT AVIATION, who played a key role in the identification of the critical problems and the realisation of experiments, within the Hermes R&D program framework.

Hypersonic Flow Theory presents the fundamentals of fluid mechanics, focusing on the hypersonic flow theory and approaches in theoretical aerodynamics. This book discusses the assumptions underlying hypersonic flow theory, unified supersonic-hypersonic similitude, two-dimensional and axisymmetric bodies, and circular cylinder. The constant-streamtube-area approximation, streamtube-continuity methods, and tangent-wedge and tangent-cone are also deliberated. This text likewise covers the similar laminar boundary layer solutions, bluntness induced interactions on slender bodies, and free molecule transfer theory. The dynamics of hypersonic flight or hypersonic wing theory, magnetohydrodynamic theory, or any developments involving treatment of the Boltzmann equation are not included. This publication is intended for hypersonic aerodynamicists, students, and researchers conducting work on the hypersonic flow phenomena.

Introduction to Hypersonic Flow has been made available to the English speaking reader because of its usefulness for those individuals desirous of obtaining an introduction to the subject. Written by an internationally acknowledged expert in the field of hypersonic flow, the book makes available heretofore unpublished Soviet work, as well as published work little known outside the Soviet Union. The author has however made every effort to include, where appropriate. Western references for the work he discusses. Starting with a general introductory chapter on hypersonic aerodynamics and aerodynamic problems, the remainder of the book concentrates on the inviscid, perfect fluid aspects of hypersonic flow, with emphasis on the fundamental concepts and rational methods of calculation. The book is directed to students of aerodynamics and gas dynamics, as well as to scientists and engineers interested in problems of hypersonic flight. The level of approach is such that it should prove particularly useful as an undergraduate and introductory graduate text.

Radioastronomy has painted an extraordinary picture of the Galactic interstellar medium, which displays an amazing organization and structuring of matter from very hot ultra-diluted media to very cold denser milieus considered as the cradles of stars. In these latter environments, the discovery of a chemical diversity of molecules, including those associated with precursors to life itself, immediately brought to light the question of the mechanisms leading to their formation and persistence at temperatures as low as 10 K. The chemical networks developed to understand telescope observations required a great deal of physical and chemical parameters relevant to interstellar conditions, particularly at very low temperatures. These included the rate coefficients of thousands of gas phase chemical reactions. Such data were missing in the 1970s, when the very first molecular discoveries were made. Then, in the early eighties, it was realized that uniform supersonic flows were ideal chemical reactors to study reaction kinetics at interstellar temperatures.Uniform Supersonic Flows in Chemical Physics reviews 40 years of use of such reactors, the so-called CRESU machines, focusing on major breakthroughs brought to chemical physics, physical chemistry, astrophysics and astrochemistry by the various experiments carried out with such apparatuses. The wealth of kinetic data at very low temperatures provided new targets for the predictions of theory, with new theoretical methods being developed to explain observed behavior. The first two chapters describe the physical context of reaction kinetics at very low temperatures and the requirements needed to run optimally such uniform supersonic flows, together with a historical perspective. Chapters 3 to 9 describe the various families of chemical processes that have been explored within the CRESU technique, highlighting major advances and offering an exhaustive up-to-date bibliography. Chapters 10 and 11 show how these experimental results have helped in improving the ideas in quantum chemistry and interstellar modeling. The book concludes with an overview of potential perspectives and new routes to be explored.

Classic and High-Enthalpy Hypersonic Flows presents a complete look at high-enthalpy hypersonic flow from a review of classic theories to a discussion of future advances centering around the Born-Oppenheim approximation, potential energy surface, and critical point for transition. The state-of-the-art hypersonic flows are defined by a seamless integration of the classic gas dynamic kinetics with nonequilibrium chemical kinetics, quantum transitions, and radiative heat transfer. The book is intended for graduate students studying advanced aerodynamics and taking courses in hypersonic flow. It can also serve as a professional reference for practicing aerospace and mechanical engineers of high-speed aerospace vehicles and propulsion system research, design, and evaluation. Features Presents a comprehensive review of classic hypersonic flow from the Newtonian theory to blast wave analogue. Introduces nonequilibrium chemical kinetics to gas dynamics for hypersonic flows in the high-enthalpy state. Integrates quantum mechanics to high-enthalpy hypersonic flows including dissociation and ionization. Covers the complete heat transfer process with radiative energy transfer for thermal protection of earth reentry vehicle. Develops and verifies the interdisciplinary governing equations for understanding and analyzing realistic hypersonic flows.