Experiments in Gasdynamics of Explosions

Oppenheim, and A K; Soloukhin, R. I.

doi:10.1146/annurev.fl.05.010173.000335

Cited by 108 publications

(31 citation statements)

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“…The soot foil technique is being used extensively for over 50 years with major contributions by Strehlow [11], Libouton et al [12] and Presles et al [13], among many others. Time resolved soot foil studies [14,15] and the mylar mirror deformation technique [16] have also been usefull to demonstrate the relationship between the cellular structure and the configuration of the shock front. The description of the detonation front structure has been considerably improved through direct visualization investigations using a variety of techniques such as interferometry [17,18], compensated streak imaging [19], direct imaging [20], schlieren [21,22,23,24] or Rayleigh scattering imaging [25].…”

Section: Introductionmentioning

confidence: 99%

Application of a laser induced fluorescence model to the numerical simulation of detonation waves in hydrogen–oxygen–diluent mixtures

Mével

Davidenko

Austin

et al. 2014

International Journal of Hydrogen Energy

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Section: Introductionmentioning

confidence: 99%

Application of a laser induced fluorescence model to the numerical simulation of detonation waves in hydrogen–oxygen–diluent mixtures

Mével

Davidenko

Austin

et al. 2014

International Journal of Hydrogen Energy

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“…The"hotspot" has been recognized to be universal to all modes of detonation initiations since it was reported as "explosion in the explosion" by Oppenheim [4]. In his paper, a sequence of typical schlieren photographs demonstrated the hotspot was generated from a turbulent flame brush and developed into a detonation bubble.…”

Section: The Role Of Hotspots In Detonation Initiationsmentioning

confidence: 99%

On the mechanism of detonation initiations

Teng

Zhang

et al. 2009

Shock Waves

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Summary. Two essential issues in detonation initiations were discussed in this paper, that is, hotspots and reaction zone acceleration. By defining the reaction zone acceleration, the hotspot and the reaction zone acceleration are identified as the primary mechanisms underlying the deflagration to detonation transition. The dominant physical process for two mechanisms is the interaction between gasdynamic non-linearity and chemical reactions that are very sensitive to temperature gradient. In the process, spontaneous waves are generated in the reaction zone, propagate with the local sound speed, decelerate suddenly in the front of the reaction zone because of the sharp temperature gradient, and develop into a pressure pulse acting to elevate the gas temperature that will further induce more intensive chemical reactions. Such a positive feedback loop supports detonation initiation and propagation.

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“…reactive gasdynamics, detonation initiation, deflagration-to-detonation transition 1 Introduction "Gasdynamics of explosions is.. .best defined as the science dealing with the interrelationship between energy transfer occurring at a high rate in a compressible medium and the concomitant motion set up in the this medium" (Oppenheim and Soloukhin, 1973). The dynamics of the interaction depend on the relationship between the dimensional time scale for substantial chemical heat release, t,, into a local region of length scale f', and local acoustic time t' = ('/a' where a' is the local speed of sound.…”

Section: Subject Termsmentioning

confidence: 99%

“…Partial inertial confinement occurs in the less exteme case t, = O(t' ) so that localized pressure increase with heat release is still possible although the expansion process occurs simultaneously with the heat addition, limiting the pressure rise and the amplitude of the compression waves. "Concomitant to (these ideas) is the appreciation of the role played in the detonation process by the power density .... at which energy is deposited into the compressible medium" (Oppenheim and Soloukhin, 1973). This quote refers to reactive gasdynamic transients specifically, where gasdynamic wave generation following a high rate of localized heat addition is crucial to facilitating fast, high temperature reaction rates.…”

Section: Subject Termsmentioning

confidence: 99%

Detonation Initiation and Evolution in Spray- Fueled Pulsed Detonation Rocket Engines

Kassoy¹,

Kuehn²,

Nabity³

et al. 2007

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The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Successful pulsed detonation engine operation requires robust, reliable, repetitive detonation initiation and evolution, up to 100 times per second. Spark-initiated combustion of fuel-oxidizer mixtures appears to be the operational technology. Our research program was designed to model the transient events following time-resolved deposition of thermal energy into a finite volume of reactive mixture. Computational solutions of the reactive Euler equations are used to predict the time history of deflagration to detonation transitions (DDT's). Solutions describe the temporal variation of the spatial distributions of temperature, pressure and fuel concentration.. The presence of shocks, localized reactive hot spots and high speed reaction zones are noted. Solution dependence on the location of the initial power deposition, the amount of power deposition and the activation energy on a one step reaction is investigated. In all cases the DDT process is facilitated by the spontaneous appearance of localized high pressure and temperature ":reaction centers" that are the subsequent sources of acoustic compression waves. The role of compressions and shocks reflected from the boundary into the partially reacted hot gas is described. The quantitative dependences of DDT evolution on the magnitude of thermal power deposition and activation energy are identified. SUBJECT

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Experiments in Gasdynamics of Explosions

Cited by 108 publications

References 1 publication

Application of a laser induced fluorescence model to the numerical simulation of detonation waves in hydrogen–oxygen–diluent mixtures

Application of a laser induced fluorescence model to the numerical simulation of detonation waves in hydrogen–oxygen–diluent mixtures

On the mechanism of detonation initiations

Detonation Initiation and Evolution in Spray- Fueled Pulsed Detonation Rocket Engines

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