Deflagration to detonation transition in large confined volume of lean hydrogen-air mixtures

Dorofeev, S.B.; Sidorov, V.P.; Dvoinishnikov, A. E.; Breitung, W.

doi:10.1016/0010-2180(95)00113-1

Cited by 100 publications

(24 citation statements)

References 8 publications

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“…RUT facility tests were performed at RRC KI with hydrogen-air mixtures with and without steam dilution in a complex geometry [ 5,6]. The first part of the facility was a channel of 2.5x2.3-m cross-section and 34.6 m long; the second part was a canyon of 6x2.5-m cross-section and 10.5 m 1ong, and the third one was a channel of 2.5x2.3-m cross-section and 20 m long.…”

Section: 2 Experimental Datamentioning

confidence: 99%

Evaluation of limits for effective flame acceleration in hydrogen mixtures

Dorofeev

Кузнецов

Алексеев

et al. 2001

Journal of Loss Prevention in the Process Industries

105

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Results of experimental data analysis on turbulent flame propagation in obstructed channels is presented. The data cover a wide range of mixtures: H 2 /air and H2/air/steam mixtures (from lean to rich) at normal and elevated initial temperatures (from 298 to 650K) and pressures (from 1 to 3 bars); and stoichiometric H 2 /02 mixtures diluted with N2, Ar, He, and C02 at normal initial conditions. The data set chosen covers, also, a wide range of scales exceeding two orders of magnitude. It is shown that basic flame parameters, such as mixture expansion ratio 0', Zeldovich number ß, and Lewis number Le, can be used to estimate a priori a potential for effective flame acceleration for a given mixture. The critical conditions for effective flame acceleration are suggested in the form f3 > l3*(Le, ß) on the basis of experimental correlations. Critical l3*-values are found tobe in the range from 3.5 to 4.0, for stable flames (ß(Le-I)> -2). For unstable flames (ß(Le-I)< -2), f3* is given by a function of Zeldovich number ß. The requirement of large enough mixture expansion ratio (J > l3*(Le, ß) can be used in practical applications as the necessary condition or criterion for possible development of fast combustion regimes. On this basis, limits for effective flame acceleration can be defined for hydrogen combustibles. Uncertainties in determination ofcritical f3*-values, which should be taken into account in practical applications, are discussed. 5. ZUSAMMENFASSUNG Bestimmung der Bedingungen für Flammenbeschleunigung in Wasserstoffhaitigen BrenngasenPractical applications and uncertainties 10Summary and conclusions 12References 13 NOMENCLATURE LatinA -elementary area of the flame surface;Csr -sound speed in reactants;Csp -sound speed in combustion products;d -size of orifice;Ea -effective activation energy;h -height of obstacles;L-characteristic geometrical size (e.g., obstacle spacing);Lr-integrallength scale of turbulence;Le -Lewis number;Le1-Lewis number defined by fuel diffusion coefficient in stoichiometric mixture;Leo -Lewis number defined by oxidizer diffusion coefficient in stoichiometric mixture;Mab -Markstein number defined relative to burned mixture; n1-reaction order for fuel;no -reaction order for oxidizer; R -gas constant;SL -laminar burning velocityrelative to unburned mixture;Tb -maximum flame temperature;Tu -initial mixture temperature;Un -normal burning velocity of stretched flames relative to burned mixture; UL -laminar burning velocity relative to burned mixture; a-ratio of densities of reactants and products ( expansion ratio);X-temperature diffusivity.

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Section: 2 Experimental Datamentioning

confidence: 99%

Evaluation of limits for effective flame acceleration in hydrogen mixtures

Dorofeev

Кузнецов

Алексеев

et al. 2001

Journal of Loss Prevention in the Process Industries

105

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“…Although direct initiation of detonation is usually considered unlikely, studies have shown that confinement and congestion can lead to detonation initiation via the deflagrationto-detonation transition (DDT) process [14]. The estimation of detonation properties, particularly cell size, is of fundamental importance for evaluation of detonation hazards in industrial processes.…”

Section: Introductionmentioning

confidence: 99%

Detonation in hydrogen–nitrous oxide–diluent mixtures: An experimental and numerical study

Mével

Davidenko

Lafosse

et al. 2015

Combustion and Flame

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“…DDT in the laboratory has been observed in several types of experiments in chambers containing cold, unreacted, exothermic gases. These include igniting the mixture with a spark (with or without obstacles along the walls of the channels, see, e.g., Oppenheim et al 1962;Laderman et al 1963;Urtiew & Oppenheim 1966;Peraldi et al 1988;Teodorczyk 1995;Dorofeev et al 1996;Dorofeev 2002) or creating a series of shock-flame interactions (e.g., Markstein et al 1964;Scarinci & Thomas 1990;Scarinci et al 1993;Thomas et al 1997Thomas et al , 2001. Experiments attempting to observe unconfined DDT (e.g., Knystautas et al 1978) showed that a transition to detonation induced by turbulent flames in systems without walls or obstacles is rather difficult.…”

Section: Introductionmentioning

confidence: 99%

Imploding Ignition Waves. I. One-Dimensional Analysis

Kushnir

Livne

Waxman

2012

ApJ

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We show that converging spherical and cylindrical shock waves may ignite a detonation wave in a combustible medium, provided the radius at which the shocks become strong exceeds a critical radius, R crit . An approximate analytic expression for R crit is derived for an ideal gas equation of state and a simple (power-law-Arrhenius) reaction law, and shown to reproduce the results of numerical solutions. For typical acetylene-air experiments we find R crit ∼ 100 μm (spherical) and R crit ∼ 1 mm (cylindrical). We suggest that the deflagration to detonation transition (DDT) observed in these systems may be due to converging shocks produced by the turbulent deflagration flow, which reaches sub-(but near) sonic velocities on scales R crit . Our suggested mechanism differs from that proposed by Zel'dovich et al., in which a fine-tuned spatial gradient in the chemical induction time is required to be maintained within the turbulent deflagration flow. Our analysis may be readily extended to more complicated equations of state and reaction laws. An order of magnitude estimate of R crit within a white dwarf at the predetonation conditions believed to lead to Type Ia supernova explosions is 0.1 km, suggesting that our proposed mechanism may be relevant for DDT initiation in these systems. The relevance of our proposed ignition mechanism to DDT initiation may be tested by both experiments and numerical simulations.

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Deflagration to detonation transition in large confined volume of lean hydrogen-air mixtures

Cited by 100 publications

References 8 publications

Evaluation of limits for effective flame acceleration in hydrogen mixtures

Evaluation of limits for effective flame acceleration in hydrogen mixtures

Detonation in hydrogen–nitrous oxide–diluent mixtures: An experimental and numerical study

Imploding Ignition Waves. I. One-Dimensional Analysis

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