Plasma-Assisted Ignition in Scramjets

Jacobsen, Lance; Carter, Campbell; Baurle, Robert A.; Jackson, Thomas

doi:10.2514/6.2003-871

Cited by 29 publications

(16 citation statements)

References 20 publications

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“…In other plasma-assisted supersonic combustion research, Jacobsen et al [49] , and NO + in large alkane reactions, point out the fundamental purpose of the plasma torch:…”

Section: Plasma-assisted 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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“…In other plasma-assisted supersonic combustion research, Jacobsen et al [49] , and NO + in large alkane reactions, point out the fundamental purpose of the plasma torch:…”

Section: Plasma-assisted 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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“…INTRODUCTION THERE IS considerable interest in the development of plasma sources having open structures. Such plasma sources have applications in a variety of areas including, spray coating and materials synthesis [1], [2], microwave reflection/absorption [3]- [5], sterilization and chemical neutralization [6], [7], shock-wave mitigation for sonic boom and wave-drag reductions in supersonic flights [8]- [10], and ignition in supersonic combustors [11]- [13]. Different applications have different requirements on the plasma parameters, such as the density, temperature, volume, and duration.…”

Section: Afrl-vs-ha-tr-2004-1133 262mentioning

confidence: 99%

Operational Characteristics of a Periodic Plasma Torch

Kuo¹,

Bivolaru²,

Carter

et al. 2004

IEEE Trans. Plasma Sci.

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Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense. Washington Headquarters Sereices, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302 Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 14. ABSTRACT Development of a plasma torch, which is intended as an ignition aide within a supersonic combustor, is studied. The high-voltage discharge and plasma plume generated by the torch module are described in a quiescent environment and in a supersonic crossflow. Voltage-current characteristics of the discharge and optical images of the plasma plume are used to characterize the operation of the torch module. The principal advantages of this torch module are its compact design, durability, and operational flexibility. The torch module can be operated in periodic or pulsed modes, depending on the power supply used. In the periodic mode presented in this paper, the capacitors are charged at the line frequency of 60 Hz resulting in a cyclical discharge at a frequency of 120 Hz. In this mode, peak and average powers reaching 8 and 2. REPORT DATE (DD-MM-YYYY) IS. SUBJECT TERMS

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“…Thermo-equilibrium plasma generator, the plasma jet (PJ) torch, contains large amount of radicals in the high temperature plasma gas and enjoys several potential advantages for combustion enhancement as a supersonic igniter [8,9,11,15,24,27]. The former studies mostly focused on the effects of feedstock [15,19,21], location of fuel injector [9] and airflow parameters on ignition characteristics for both hydrogen and hydrocarbon fuels.…”

Section: Introductionmentioning

confidence: 99%

“…For supersonic combustion, the global ignition concept is introduced for the definition of successful ignition [8]. That means, pre-combustion shock train can be established upstream of fuelinjection/flame-holding, and the resulting heat release in the combustion chamber make this process self-sustaining, and also there is no too much backpressure for un-starting of engine inlet.…”

Section: Introductionmentioning

confidence: 99%

Plasma-assisted ignition for a kerosene fueled scramjet at Mach 1.8

Tong

et al. 2013

Aerospace Science and Technology

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By using a plasma jet (PJ) torch with 1.5 kW input power as an igniter, successful ignition for liquidkerosene fueled combustion experiment was conducted in a direct-connected supersonic test facility. The incoming flow has total temperature of 950 K and local Mach number of 1.8, corresponding to Mach 4 flight condition. In this study, several optical techniques, including high speed photography, high speed schlieren photography, and planar laser scattering (PLS) technique, were combined to study the ignition process, flame propagation, and mixing features of liquid kerosene fuel with air around the cavity. The effect of fuel injection position, injection pressure, and feedstock gas on ignition performance has been analyzed. The results indicate that local mixing is a critical factor for ignition. It is also shown that the PJ torch with N 2 + H 2 feedstock is superior to the PJ torch with N 2 feedstock for the ignition of liquidkerosene fuel. These results are valuable for the future optimization of kerosene-fueled scramjet engine when using a PJ torch as an igniter.

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Plasma-Assisted Ignition in Scramjets

Cited by 29 publications

References 20 publications

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

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

Operational Characteristics of a Periodic Plasma Torch

Plasma-assisted ignition for a kerosene fueled scramjet at Mach 1.8

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