The objective of the study is to obtain data on turbulent, supersonic combustion which will facilitate development of ignition systems for use in scramjet engines under conditions when combustion cannot occur spontaneously. To this end a simple analytical model of a reacting, turbulent flow is presented, based upon the a priori assumption that combustion and turbulent mixing can be uncoupled. Predictions from this model are compared with some new experimental data on the ignition of ethylene in air. Both premixed and unpremixed situations are included. Tests of the validity of the mixing model are made for the nonreacting case by comparing predicted and measured velocity profiles in a duct; a satisfactory agreement is obtained. The predicted ignition requirements also match the measured values in most cases, with mixing- and reaction-rate data taken from the literature. Until uncertainties in these mixing- and reaction-rate expressions can be substantially reduced, the use of more subtle coupling models in the determination of ignition requirements does not appear to be justified. A much simpler model is also presented and used to derive a useful criterion for the prediction of the ignition boundaries in premixed fuel-air flows. (Author).

A theoretical study has been made of the phenomenon of ignition, by hot gas jets, of combustible turbulent, supersonic flows. Although based upon some questionable assumptions, the theory predicts minimum jet conditions for ignition in agreement with experimental results obtained so far. An existing computer program has been modified to predict composition and velocity distributions in the fuel-air mixing regions, but some empirical constants must be obtained by further experiments. (Author).

This book describes the unsteady phenomena needed to understand supersonic combustion. Following an initial chapter that introduces readers to the basic concepts in and classical studies on unsteady supersonic combustion, the book highlights recent studies on unsteady phenomena, which offer insights on e.g. interactions between acoustic waves and flames, flow dominating instability, ignition instability, flame flashback, and near-blowout-limit combustion. In turn, the book discusses in detail the fundamental mechanisms of these phenomena, and puts forward practical suggestions for future scramjet design.

A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA)

Proceedings of the XXth International Astronautical Congress compiles selected papers presented at the 20th International Astronautical Congress held in Mar del Plata, Argentina in 1969. This book is divided into five main topics—spacecraft engineering, astrodynamics, astrionics, bioastronautics, and problems of education. In these topics, this compilation specifically discusses the equatorial vibrations of a long flexible boom on a spin-stabilized satellite of non-zero radius; heat transfer to linear bodies in two-dimensional hypersonic low density; and limits of accuracy of general perturbations for satellites moving under constant forces. The rapid optimization of multiple-burn rocket flights; data transmission for planetary studies; and comparison of theoretical and experimental attitude data for the DODGE spacecraft are also elaborated. This text also covers the Apollo life-support and protective systems; bioastronautical aspects of Apollo biomedical operations; and development and applications of hot water rockets. This publication is recommended for astrophysicists and scientists of other disciplines related to astronomy.