Studies in connection with stabilized gaseous detonation waves

Nicholls, J. A.; Dabora, Eliahou K.; Gealer, Roy Lee

doi:10.1016/s0082-0784(58)80118-6

Cited by 36 publications

(16 citation statements)

References 2 publications

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“…First studies by Nicholls et al 22 as well as Gross and Chinitz 15 in the 1950's confirmed the possibility of stabilizing an oblique shock wave at high Mach numbers. Additionally, studies 14 have shown numerically the stability of detonations in unsteady flows.…”

Section: Shock-induced Combustionmentioning

confidence: 92%

Numerically Simulated Comparative Performance of a Scramjet and Shcramjet at Mach 11

Chan

Sislian

Alexander

2010

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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This study investigates the design and aeropropulsive performance of a complete, hydrogen powered, shock-induced combustion ramjet (shcramjet) at a flight Mach number of 11 and altitude of 34.5 km. The design includes a Prandtl-Meyer compression inlet, cantilevered ramp fuel injectors, a shock-inducing wedge and a divergent nozzle. Numerical studies are undertaken using the WARP code that solves the three-dimensional Favre-averaged Navier-Stokes equations closed by the Wilcox k-ω turbulence model and the Jachimowski H 2 /air chemical kinetics model. Studies of fuel injection properties, mixing duct length, combustor wedge and nozzle geometry are completed to maximize the overall performance of the vehicle. The final shcramjet configuration generates a specific impulse of 1110 s. A comparison is undertaken with a scramjet vehicle at identical flight conditions and using many of the same components. The comparable scramjet generates a higher specific impulse of 1450 s although it is significantly larger and therefore heavier.ii

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Section: Shock-induced Combustionmentioning

confidence: 92%

Numerically Simulated Comparative Performance of a Scramjet and Shcramjet at Mach 11

Chan

Sislian

Alexander

2010

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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“…In 1958, Nicholls et al [1] explored the possibility of using a stabilized detonation wave to achieve supersonic combustion for a high Mach number ramjet. Results showed that an underexpanded axisymmetric jet of supersonic gaseous hydrogen and air was ignited by a strong normal shock, or Mach disc, and an ignition delay time of about 25 µsec was reported.…”

Section: Challenges To Supersonic Combustionmentioning

confidence: 99%

Plasma Torch Atomizer-Igniter for Supersonic Combustion of Liquid Hydrocarbon Fuels

Billingsley¹,

O’Brien²,

Schetz³

2006

14th AIAA/AHI Space Planes and Hypersonic Systems and Technologies Conference

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To realize supersonic combustion of hydrocarbons, an effective atomizer-igniter combination with the capabilities of fuel preheating, atomization, penetration, mixing, ignition and flameholding is desired. An original design concept incorporating these capabilities was built and tested at Virginia Tech, and was found to provide good penetration, effective atomization, and robust ignition and flameholding. Quiescent testing with kerosene and JP-7 provided initial performance data. The atomizer-injector design was then modified for insertion In the quiescent environment, the regeneratively cooled plasma torch igniter was found to significantly increase electrode life while heating, atomizing, and igniting the liquid fuel. Jet breakup length was measured and characterized, and mean droplet size was estimated using an existing correlation. Several qualitative observations regarding quiescent combustion were made, including torch power effects and the process of flame formation. In the supersonic environment, the effect of fuel injection direction was analyzed. Best results were obtained when fuel was injected with a velocity component opposite to the direction of main tunnel flow. Repeatable ignition occurred in the supersonic boundary layer at the fuel stagnation location near the plasma torch plume. Direct, filtered, shadowgraph, and schlieren photographs, temperature ii measurements, and visible emission spectroscopy provided evidence of combustion and the details of the flame structure.The new atomizer-igniter design provided robust and reliable ignition and flameholding of liquid hydrocarbon fuels in an unheated supersonic flow at M=2.4, with no ramp, step, or other physical penetration into the flowpath.iii Acknowledgements Dr. O'Brien, I enjoyed the relaxed lab atmosphere, and am grateful for your unique ability to promote progress without being overbearing. Thank you for recognizing my circumstances, and being flexible as I managed my young family. Thank you for the enthusiasm you show for your research; it was a privilege and a joy working with you.

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“…14. Conceptually, flow over a wedge or a standing wave in a jet or nozzle is the simplest configuration. Early experiments were carried out by Gross and Chinitz (1960) using wedges and Nicholls et al (1959) using jets. Although the terms "standing detonation wave" are often used in connection with these experiments, very little effect of combustion on the shock wave could be observed (Nicholls 1963) and the terms "shock-induced combustion" are more appropriate.…”

Section: Experiments On Bcstationary" Detonation Wavesmentioning

confidence: 99%

Detonation Waves and Propulsion

Shepherd

1994

ICASE/LaRC Interdisciplinary Series in Science and Engineering

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The possibility of using a detonation wave as the key combustion system for supersonic propulsion is examined. A brief review of propagating detonations is provided first. This review emphasizes the unique and unstable nature of the coupling between reaction zone and shock waves that characterize detonations. The theory of idealized, steady, oblique detonation waves and their reaction zone structure are summarized. The evidence for the existence of stabilized or steady oblique detonations is discussed. Experiments with multiple layers of explosive and projectiles fired into explosive gases are examined. There are a variety of reasons that these previous studies have failed to produce stabilized detonations. A brief catalog of difficulties is provided and based on andogies with our knowledge of propagating detonations, a set of criteria are proposed for the existence and stability of stabilized detonations. The problems of initiation and instability are examined for the situation of a flow over a wedge.

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Studies in connection with stabilized gaseous detonation waves

Cited by 36 publications

References 2 publications

Numerically Simulated Comparative Performance of a Scramjet and Shcramjet at Mach 11

Numerically Simulated Comparative Performance of a Scramjet and Shcramjet at Mach 11

Plasma Torch Atomizer-Igniter for Supersonic Combustion of Liquid Hydrocarbon Fuels

Detonation Waves and Propulsion

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