Effect of ignition position on the run-up distance to DDT for hydrogen–air explosions

Blanchard, Robert; Arndt, Detlef; Grätz, Rainer; Scheider, Swen

doi:10.1016/j.jlp.2010.12.007

Cited by 43 publications

(10 citation statements)

References 13 publications

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“…Our exploratory numerical tests have shown that the described effect holds also for fully nonlinear quasi-one-dimensional (figure 14) as well as two-dimensional formulations allowing for shocks and conventional supersonic detonations. The plots of figure 14 are qualitatively in line with recent experimental studies by Blanchard et al [48], thereby providing a new argument in support of the resistance concept of the DDT.…”

Section: Minimal Model: Shchelkin's Effectsupporting

confidence: 86%

Combustion waves in hydraulically resisted systems

Brailovsky

Kagan

Sivashinsky

2012

Phil. Trans. R. Soc. A.

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The effects of hydraulic resistance on the burning of confined/obstacle-laden gaseous and gas-permeable solid explosives are discussed on the basis of recent research. Hydraulic resistance is found to induce a new powerful mechanism for the reaction spread (diffusion of pressure) allowing for both fast subsonic as well as supersonic propagation. Hydraulic resistance appears to be of relevance also for the multiplicity of detonation regimes as well as for the transitions from slow conductive to fast convective, choked or detonative burning. A quasi-one-dimensional Fanno-type model for premixed gas combustion in an obstructed channel open at the ignition end is discussed. It is shown that, similar to the closed-end case studied earlier, the hydraulic resistance causes a gradual precompression and preheating of the unburned gas adjacent to the advancing deflagration, which leads (after an extended induction period) to a localized autoignition that triggers an abrupt transition from deflagrative to detonative combustion. In line with the experimental observations, the ignition at the open end greatly encumbers the transition (compared with the closed-end case), and the deflagration practically does not accelerate up to the very transition point. Shchelkin's effect, that ignition at a small distance from the closed end of a tube facilitates the transition, is described.

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Section: Minimal Model: Shchelkin's Effectsupporting

confidence: 86%

Combustion waves in hydraulically resisted systems

Brailovsky

Kagan

Sivashinsky

2012

Phil. Trans. R. Soc. A.

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“…So DDT is completed between P2 and P3. In addition, the high detonation waves prove that the detonation initiation point is after P2 [8,32]. The DDT time and distance of numerical simulation have good similarity with the experiment.…”

Section: Grid-independent and Model Validationmentioning

confidence: 53%

“…They indicated that wall ignition had advantages over closed-end ignition in the initiation time and distance of DDT. Blanchard et al [32] studied the effects of different wall ignition positions on flame propagation and DDT by hydrogen/air experiments. The results showed that the expansion of burnt fuel against the closed section of the tube behind flame front increased flame speed and turbulence when the ignition position was a certain distance from the closed section.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Hot Jet Detonation with Different Ignition Positions

et al. 2019

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Ignition position is an important factor affecting flame propagation and deflagration-to-detonation transition (DDT). In this study, 2D reactive Navier–Stokes numerical studies have been performed to investigate the effects of ignition position on hot jet detonation initiation. Through the stages of hot jet formation, vortex-flame interaction and detonation wave formation, the mechanism of the hot jet detonation initiation is analyzed in detail. The results indicate that the vortexes formed by hot jet entrain flame to increase the flame area rapidly, thus accelerating energy release and the formation of the detonation wave. With changing the ignition position from top to wall inside the hot jet tube, the faster velocity of hot jet will promote the vortex to entrain jet flame earlier, and the DDT time and distance will decrease. In addition, the effect of different wall ignition positions (from 0 mm to 150 mm away from top of hot jet tube) on DDT is also studied. When the ignition source is 30 mm away from the top of hot jet tube, the distance to initiate detonation wave is the shortest due to the highest jet intensity, the DDT time and distance are about 41.45% and 30.77% less than the top ignition.

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“…4). The run-up distance for the defl agration to detonation transition was investigated by BAM researchers (Blanchard et al, 2011).…”

Section: Current Research -Safety Of Gases and Gas Installationsmentioning

confidence: 99%

Industrial Safety - Public Demand and an Answer of Bam the Federal German Institute for Materials Research and Testing

Lexow¹

2014

TRANSACTIONS of the VŠB – Technical University of Ostrava, Safety Engineering Series

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Safe industrial operation is expected by the public. It contributes to a clean environment, innovation and prosperity. BAM the Federal German Institute for Materials Research and Testing has its responsibility in further developing safety in technology and chemistry by research, testing and expert advice. The basic reasoning for this activity and examples of current work are provided. Particular attention is given to the unique BAM Test site Technical Safety. Acceptance of findings and transfer of results are based on collaboration and exchange of personal. Modes of cooperation are described.

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Effect of ignition position on the run-up distance to DDT for hydrogen–air explosions

Cited by 43 publications

References 13 publications

Combustion waves in hydraulically resisted systems

Combustion waves in hydraulically resisted systems

Numerical Simulation of Hot Jet Detonation with Different Ignition Positions

Industrial Safety - Public Demand and an Answer of Bam the Federal German Institute for Materials Research and Testing

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