On the mechanism of the deflagration-to-detonation transition in a hydrogen-oxygen mixture
- Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)
- Moscow State University, Institute of Nuclear Physics (Russian Federation)
The flame acceleration and the physical mechanism underlying the deflagration-to-detonation transition (DDT) have been studied experimentally, theoretically, and using a two-dimensional gasdynamic model for a hydrogen-oxygen gas mixture by taking into account the chain chemical reaction kinetics for eight components. A flame accelerating in a tube is shown to generate shock waves that are formed directly at the flame front just before DDT occurred, producing a layer of compressed gas adjacent to the flame front. A mixture with a density higher than that of the initial gas enters the flame front, is heated, and enters into reaction. As a result, a high-amplitude pressure peak is formed at the flame front. An increase in pressure and density at the leading edge of the flame front accelerates the chemical reaction, causing amplification of the compression wave and an exponentially rapid growth of the pressure peak, which 'drags' the flame behind. A high-amplitude compression wave produces a strong shock immediately ahead of the reaction zone, generating a detonation wave. The theory and numerical simulations of the flame acceleration and the new physical mechanism of DDT are in complete agreement with the experimentally observed flame acceleration, shock formation, and DDT in a hydrogen-oxygen gas mixture.
- OSTI ID:
- 21443361
- Journal Information:
- Journal of Experimental and Theoretical Physics, Journal Name: Journal of Experimental and Theoretical Physics Journal Issue: 4 Vol. 111; ISSN 1063-7761
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ACCELERATION
AMPLIFICATION
AMPLITUDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COMPRESSION
COMPUTERIZED SIMULATION
DENSITY
DETONATION WAVES
DISPERSIONS
ELEMENTS
EXPLOSIONS
FLAMES
HYDROGEN
KINETICS
LAYERS
MIXTURES
NONMETALS
OXYGEN
PHYSICAL PROPERTIES
REACTION KINETICS
SHOCK WAVES
SIMULATION