A Caltech Library Service

Detonation Initiation in a Tube via Imploding Toroidal Shock Waves

Jackson, S. I. and Shepherd, J. E. (2008) Detonation Initiation in a Tube via Imploding Toroidal Shock Waves. AIAA Journal, 46 (9). pp. 2357-2367. ISSN 0001-1452. doi:10.2514/1.35569.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


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.

Item Type:Article
Related URLs:
URLURL TypeDescription DOIArticle
Shepherd, J. E.0000-0003-3181-9310
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.
Funding AgencyGrant Number
Office of Naval ResearchN00014-03-1-0931
NASA Graduate Student Research FellowshipNGT8-52937
Issue or Number:9
Record Number:CaltechAUTHORS:20100506-135353183
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:18169
Deposited By: Tony Diaz
Deposited On:10 May 2010 03:19
Last Modified:08 Nov 2021 23:41

Repository Staff Only: item control page