An attempt is made to reflect on current focuses in certain areas of hypersonic flow research by examining recent works and their issues. Aspects of viscous interaction, flow instability, and nonequilibrium aerothermodynamics pertaining to theoretical interest are focused upon. The field is a diverse one, and many exciting works may have either escaped the writer's notice or been abandoned for the sake of space. Students of hypersonic viscous flow must face the transition problems towards the two opposite ends of the Reynolds or Knudsen number range, which represents two regimes where unresolved fluid/gas dynamic problems abound. Central to the hypersonic flow studies is high-temperature physical gas dynamics; here, a number of issues on modelling the intermolecular potentials and inelastic collisions remain the obstacles to quantitative predictions. Research in combustion and scramjet propulsion will certainly be benefitted by advances in turbulent mixing and new computational fluid dynamics (CFD) strategies on multi-scaled complex reactions. Even for the sake of theoretical development, the lack of pertinent experimental data in the right energy and density ranges is believed to be among the major obstacles to progress in aerothermodynamic research for hypersonic flight. To enable laboratory simulation of nonequilibrium effects anticipated for transatmospheric flight, facilities capable of generating high enthalpy flow at density levels higher than in existing laboratories are needed (Hornung 1988). A new free-piston shock tunnel capable of realizing a test-section stagnation temperature of 10(exp 5) at Reynolds number 50 x 10(exp 6)/cm is being completed and preliminary tests has begun (H. Hornung et al. 1992). Another laboratory study worthy of note as well as theoretical support is the nonequilibrium flow experiment of iodine vapor which has low activation energies for vibrational excitation and dissociation, and can be studied in a laboratory with modest resou...

Progress in Astronautics and Rocketry, Volume 7: Hypersonic Flow Research compiles papers presented at a conference on hypersonics held at the Massachusetts Institute of Technology in August 1961. This book discusses the low Reynolds number effects, chemical kinetics effects, inviscid flow calculations, and experimental techniques relating to the problems in acquiring an understanding of hypersonic flow. The structure and composition of hypersonic wakes with attendant complex chemical kinetic effects is only briefly mentioned. This text consists of five parts. Parts A to C comprise of theoretical papers on the problems of calculating flow fields at hypersonic speeds. The experimental techniques that are of immediate practical interest in view of the difficulty of flight testing are discussed in Parts D and E. This publication is beneficial to engineers involved in advanced design problems.

This book covers classical and modern aerodynamics, theories and related numerical methods, for senior and first-year graduate engineering students, including: -The classical potential (incompressible) flow theories for low speed aerodynamics of thin airfoils and high and low aspect ratio wings. - The linearized theories for compressible subsonic and supersonic aerodynamics. - The nonlinear transonic small disturbance potential flow theory, including supercritical wing sections, the extended transonic area rule with lift effect, transonic lifting line and swept or oblique wings to minimize wave drag. Unsteady flow is also briefly discussed. Numerical simulations based on relaxation mixed-finite difference methods are presented and explained. - Boundary layer theory for all Mach number regimes and viscous/inviscid interaction procedures used in practical aerodynamics calculations. There are also four chapters covering special topics, including wind turbines and propellers, airplane design, flow analogies and hypersonic (rotational) flows. A unique feature of the book is its ten self-tests and their solutions as well as an appendix on special techniques of functions of complex variables, method of characteristics and conservation laws and shock waves. The book is the culmination of two courses taught every year by the two authors for the last two decades to seniors and first-year graduate students of aerospace engineering at UC Davis.