Mechanisms of deflagration-to-detonation transition under initiation by high-voltage nanosecond discharges

Journal Article · Wed Oct 15 00:00:00 EDT 2008 · Combustion and Flame

DOI:https://doi.org/10.1016/J.COMBUSTFLAME.2008.05.019· OSTI ID:21116116

Rakitin, Aleksandr E; Starikovskii, Andrei Yu ^[1]

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1. Physics of Nonequilibrium Systems Lab, Moscow Institute of Physics and Technology, 9 Institutski Lane, Dolgoprudny 141700 (Russian Federation)

An experimental study of detonation initiation in a stoichiometric propane-oxygen mixture by a high-voltage nanosecond gas discharge was performed in a detonation tube with a single-cell discharge chamber. The discharge study performed in this geometry showed that three modes of discharge development were realized under the experimental conditions: a spark mode with high-temperature channel formation, a streamer mode with nonuniform gas excitation, and a transient mode. Under spark and transient initiation, simultaneous ignition inside the discharge channel occurred, forming a shock wave and leading to a conventional deflagration-to-detonation transition (DDT) via an adiabatic explosion. The DDT length and time at 1 bar of initial pressure in the square smooth tube with a 20-mm transverse size amounted to 50 mm and 50{mu}s, respectively. The streamer mode of discharge development at an initial pressure of 1 bar resulted in nonuniform mixture excitation and a successful DDT via a gradient mechanism, which was confirmed by high-speed time resolved ICCD imaging. The gradient mechanism implied a longer DDT time of 150{mu}s, a DDT run-up distance of 50 mm, and an initiation energy of 1 J, which is two orders of magnitude less than the direct initiation energy for a planar detonation under these conditions. (author)

• OSTI ID: 21116116
• Journal Information: Combustion and Flame, Journal Name: Combustion and Flame Journal Issue: 1-2 Vol. 155; ISSN CBFMAO; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ADIABATIC PROCESSES
COMBUSTION KINETICS
DISTANCE
Deflagration-to-detonation transition
ELECTRIC SPARKS
EXCITATION
EXPLOSIONS
Gradient mechanism
IGNITION
MIXTURES
Nanosecond discharges
OXYGEN
PRESSURE RANGE KILO PA
PROPANE
SHOCK WAVES
STOICHIOMETRY
TRANSIENTS
TUBES
VELOCITY