Brief communication. Transition to detonation in a large fuel-air cloud


  1. Moen, I.O.
  2. Bjerketvedt, D.
  3. Jenssen, A.
  4. Thibault, P.A.
Corporate Authors
Defence Research Establishment Suffield, Ralston ALTA (CAN)
In assessing the blast hazards from fuel-air vapor cloud explosions, the possibility of transition from deflagration to detonation is of utmost concern. If such transition does occur, the resulting detonation will propagate throughout the cloud generating overpressures in excess of 15 atm. Most of the reported observations of transition from deflagration to detonation are for either sensitive fuel-oxygen mixtures or heavily confined configurations. The transition processes for hydrogen-oxygen mixtures in a confined tube have been revealed with unsurpassed clarity by the stroboscopic laser schlieren photographs of Urtiew and Oppenheim. From these photographs it can be seen that the key feature associated with the onset of detonation is the formation of a localized explosion somewhere within the turbulent flame shock wave region. Transitions from deflagration to detonation in fuel-air mixtures have also been observed in confined tubes. In these cases the critical conditions for the onset of detonation are achieved by the acceleration of the flame to some critical speed. Whether sufficiently high flame speeds for transition by similar mechanisms can be achieved under less confined conditions has not been clarified. TRUNCATED
Shock initiation;Transition to detonation;DDT (Deflagration to Detonation Transition)
Date of publication
12 Mar 2001
Number of Pages
Reprinted from
Combustion and Flame, Vol 61, 1985, p 285-291
Hardcopy;Document Image stored on Optical Disk

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