Progress Toward Shock Enhancement of Supersonic Combustion Processes

In air breathing propulsion systems for flight at Mach numbers 7 to 20, it is generally accepted that the combustion processes will be carried out at supersonic velocities with respect to the engine. The resulting brief residence time places a premium on rapid mixing of the fuel and air. To address this issue we &re investigating a mechanism for enhancing the rate of mixing between air and hydrogen fuel over rates that are expected in shear layers and jets. The mechanism rests upon the strong vorticity induced at the interface between a light and heavy gas by an intense pressure gradient. The specific phenomenon under investigation is the rapid mixing induced by interaction of a weak oblique shock with a cylindrical jet of hydrogen embedded in air. The status of our investigations is described in three parts: a) shock tube investigation of the distortion and mixing induced by shock waves impinging on cylindric of hydrogen embedded in air, b) the molecular mixing and chemical reaction in large vortices, periodically formed in a channel, and c) two-dimensional non-steady and three-dimensional steady numerical studies of shock interaction with cylindrical volumes of hydrogen in air.

[1]  P. Waltrup,et al.  Liquid fueled supersonic combustion ramjets - A research perspectiveof the past, present and future , 1986 .

[2]  B. Sturtevant,et al.  A 17-INCH DIAMETER SHOCK TUBE FOR STUDIES IN RAREFIED GASDYNAMICS , 1962 .

[3]  H. Neale Kelly,et al.  Actively cooled airframe structures for high-speed flight , 1977 .

[4]  J. P. Weidner,et al.  Studies of scramjet/airframe integration techniques for hypersonic aircraft , 1975 .

[5]  G. Hendricks,et al.  Two Mechanisms of Vorticity Generation in Combusting Flow Fields , 1986 .

[6]  G. Rudinger,et al.  Behaviour of small regions of different gases carried in accelerated gas flows , 1960, Journal of Fluid Mechanics.

[7]  J. Boris,et al.  Theory of Vorticity Generation by Shock Wave and Flame Interactions , 1984 .

[8]  Frank E. Marble,et al.  Growth of a Diffusion Flame in the Field of a Vortex , 1985 .

[9]  G. Y. Anderson,et al.  Supersonic Mixing and Combustion in Parallel Injection Flow Fields , 1975 .

[10]  Antonio Ferri,et al.  Mixing-Controlled Supersonic Combustion , 1973 .

[11]  W. J. Small,et al.  Scramjet nozzle design and analysis as applied to a highly integrated hypersonic research airplane , 1974 .

[12]  Frank E. Marble,et al.  Study of a Diffusion Flame in a Stretched Vortex , 1986 .

[13]  E. Zukoski,et al.  Combustion instability sustained by unsteady vortex combustion , 1985 .

[14]  F. Harlow,et al.  Interaction of Shock or Rarefaction with a Bubble , 1962 .

[15]  Duane A. Smith.  An Experimental Study of Acoustically Excited, Vortex Driven, Combustion Instability within a Rearward Facing Step Combustor , 1985 .

[16]  R. Gross.  Recent Advances in Gaseous Detonation , 1959 .

[17]  Alan H. Epstein.  Quantitative Density Visualization in a Transonic Compressor Rotor , 1977 .

[18]  C. R. Mcclinton.  Interaction between step fuel injectors on opposite walls in a supersonic combustor model , 1978 .

[19]  James L. Hunt,et al.  Hypersonic transport technology , 1977 .

[20]  Jay P. Boris,et al.  Vorticity Generation by Asymmetric Energy Deposition in a Gaseous Medium. , 1983 .

[21]  A. Karagozian,et al.  Flame Structure and Fuel Consumption in the Field of a Vortex Pair , 1986 .

[22]  A. Ferri,et al.  Review of scramjet propulsion technology. , 1968 .