Detonation Initiation in a Tube via Imploding Toroidal Shock Waves
- Creators
- Jackson, S. I.
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Shepherd, J. E.
Abstract
The effectiveness of imploding waves at detonation initiation of stoichiometric ethylene- and propane–oxygen– nitrogen mixtures in a tube was investigated. Implosions were driven by twice-shocked gas located at the end of a shock tube, and wave strength was varied to determine the critical conditions necessary for initiation as a function of diluent concentration for each fuel. Hydrocarbon–air mixtures were not detonated due to facility limitations, however, detonations were achieved with nitrogen dilutions as large as 60 and 40% in ethylene and propane mixtures, respectively. The critical-energy input required for detonation of each dilution was then estimated using the unsteady energy equation. Blast-wave initiation theory was reviewed and the effect of tube wall proximity to the blast-wave source was considered. Estimated critical energies were found to scale better with the planar initiation energy than the spherical initiation energy, suggesting that detonation initiation was influenced by wave reflection from the tube walls.
Additional Information
© 2008 by California Institute of Technology. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. Presented as Paper 3919 at the 40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, Fort Lauderdale, FL, 11–14 July 2004; received 16 November 2007; revision received 19 March 2008; accepted for publication 27 March 2008. This work was supported by the Office of Naval Research (Grant No. N00014-03-1-0931: Detonation Initiation by Annular Jets and Shock Waves) and the NASA Graduate Student Researchers Program (Grant No. NGT8-52937: Initiation System for Pulse Detonation Engines). The authors are grateful to J. Blevins and C. Morris at NASA Marshall Space Flight Center for their support, and would also like to acknowledge discussions on shock implosion with C. Li and K. Kailasanath. We would like to thank P. Buraczewski for his design work as well as J. Haggerty, B. St. John, and A. Kiani for their machining skills.Attached Files
Published - Jackson2008p8826Aiaa_J.pdf
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Additional details
- Eprint ID
- 18169
- Resolver ID
- CaltechAUTHORS:20100506-135353183
- Office of Naval Research
- N00014-03-1-0931
- NASA Graduate Student Research Fellowship
- NGT8-52937
- Created
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2010-05-10Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field
- Caltech groups
- GALCIT