Unsteady Supersonic Combustion

Unsteady Supersonic Combustion
Author: Mingbo Sun
Publisher: Springer Nature
Total Pages: 380
Release: 2020-04-14
Genre: Technology & Engineering
ISBN: 9811535957

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.

Mechanisms of Unsteady Flow in Scramjet Combustors

Mechanisms of Unsteady Flow in Scramjet Combustors
Author:
Publisher:
Total Pages: 0
Release: 1998
Genre:
ISBN:

This report covers analytic and experimental gasdynamic studies relevant to stability issues of the scramjet supersonic combustion chamber. Its intended purpose was to search for small amplitude very short time scale precurser signals which eventually grew into combustor flow instability, but at a much longer time scale than the signal itself, and consequently offer possibility of control before amplitudes got out of hand. The experiments were done in a basic 2.5 Mach number stream with an artificially thickened boundary layer corresponding to the ingested ramp boundary layer that occurs in the usual installation . A disturbance produced downstream by a small shock tube discharging normally to the gas flow successfully disgorged the shock structure; time resolved pressure and Schlieren image records were obtained. Because upstream signal propagation through the subsonic boundary layer of a supersonic flow is seen as an important issue in the phenomenon under investigation, a rudamentary analytic model was developed. It consists of an acoustically compact element, in which mixing and heat release may occur, with long constant area ducts upstream and downstream of this element. It employs a two stream one dimensional approximation, the main supersonic stream and a subsonic second stream representing the thick boundary layer. Conditions under which interfacial disturbances may be propagated upstream are examined through several examples.

Combustion in High-Speed Flows

Combustion in High-Speed Flows
Author: John Buckmaster
Publisher: Springer Science & Business Media
Total Pages: 639
Release: 2012-12-06
Genre: Technology & Engineering
ISBN: 9401110506

This volume contains the proceedings of the Workshop on Com bustion, sponsored by the Institute for Computer Applications in Science and Engineering (ICASE) and the NASA Langley Research Center (LaRC). It was held on October 12-14, 1992, and was the sec ond workshop in the series on the subject. The first was held in 1989, and its proceedings were published by Springer-Verlag under the title "Major Research Topics in Combustion," edited by M. Y. Hussaini, A. Kumar, and R. G. Voigt. The focus of the second workshop was directed towards the development, analysis, and application of basic models in high speed propulsion of particular interest to NASA. The exploration of a dual approach combining asymptotic and numerical methods for the analysis of the models was particularly encouraged. The objectives of this workshop were i) the genesis of models that would capture or reflect the basic pllysical phenomena in SCRAMJETs and/or oblique detonation-wave engines (ODWE), and ii) the stimulation of a greater interaction between NASA exper imental research community and the academic community. The lead paper by D. Bushnell on the status and issues of high speed propulsion relevant to both the SCRAMJET and the ODWE parallels his keynote address which set the stage of the workshop. Following the lead paper were five technical sessions with titles and chairs: Experiments (C. Rogers), Reacting Free Shear Layers (C. E. Grosch), Detonations (A. K. Kapila), Ignition and Struc ture (J. Buckmaster), and Unsteady Behaviour ('1'. L. Jackson).