Detonation Initiation by Annular Jets and Shock Waves
Abstract
This project was an experimental test of the concept of initiating detonations in PDEs with imploding shock waves. The existing 6-inch shock tube at Caltech was used to create hot, high pressure air behind a reflected shock wave. The hot air created an imploding annular shock wave when it jetted through an annular orifice into a 76 mm diameter, 1 m long tube attached to the end of the shock tube. The test tube was filled with either stoichiometric ethylene-oxygen or propane-oxygen diluted with nitrogen. Piezoelectric pressure transducers and ionization gauges were used to determine the type of combustion event initiated by the annular jet of hot air. The stagnation conditions in the shock tube and the amount of dilution with nitrogen in the test section were varied to find the critical conditions for the onset of detonation in each test mixture. Less sensitive (high dilution) mixtures required larger stagnation pressures in order to initiate a detonation. We were unable to initiate either ethylene or propane-air mixtures within our facility limits. Extrapolation of the low-dilution data indicates that very high stagnation pressures (> 16 bar) are required.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 05, 2005
- Accession Number
- ADA433330
Entities
People
- Joseph E. Shepherd
Organizations
- California Institute of Technology