Analysis of the final stage of flame acceleration and the onset of detonation in a cylindrical tube using high-speed stereoscopic imaging

Krivosheyev, P. N.; Penyazkov, O. G.; Sakalou, Aliaksei

doi:10.1016/j.combustflame.2020.02.027

Cited by 30 publications

(5 citation statements)

References 54 publications

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“…Then, the non-flat reaction region propagated with subsequent acceleration and deflagration to detonation transition (DDT) occurred. In this case, the near-wall effects (boundary layer and its interaction with additional compression waves) can influence the self-ignition and DDT [26,27].…”

Section: Resultsmentioning

confidence: 99%

Ignition Delay and Reaction Time Measurements of Hydrogen–Air Mixtures at High Temperatures

Baranyshyn,

Kuzmitski,

Penyazkov

et al. 2024

Fire

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Induction and reaction times of hydrogen–air mixtures (ϕ = 0.5–2) have been measured behind reflected shock waves at temperatures of 1000–1600 K, pressures of 0.1, 0.3, 0.6 MPa in the domain of the extended second explosion limit. The measurements were performed in the shock tube with a completely transparent test section of 0.5 m long, which provides pressure, ion current, OH and high-speed chemiluminescence observations. The experimental induction time plots demonstrate a clear increasing of the global activation energy from high- to low temperature post-shock conditions. This trend is strongly pronounced at higher post-shock pressures. For a high-temperature range of T > 1200 K, induction time measurements show an activation energy for the global reaction rate of hydrogen oxidation of 64–83 kJ/mole. Detected reaction times exhibit a big scatter and a weak temperature dependence. The minimum reaction time value was nearly 2 µs. Obtained induction time data were compared with calculations carried out in accordance with the known kinetic mechanisms. For current and former shock-tube experiments within a pressure range of 0.1–2 MPa, critical temperatures required for strong (1000–1100 K), transient and weak auto-ignition modes behind reflected shock waves were identified by means of the pressure and ion-probe measurements in stoichiometric hydrogen-air mixture. The transfer from the strong volumetric self-ignition near the reflecting wall to the hot spot ignition (transient) was established and visualized below <1200 K with a post-shock temperature decreasing.

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Section: Resultsmentioning

confidence: 99%

Ignition Delay and Reaction Time Measurements of Hydrogen–Air Mixtures at High Temperatures

Baranyshyn,

Kuzmitski,

Penyazkov

et al. 2024

Fire

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“…the main reason for such an temperature increase should more properly be linked to the non-isentropic processes that occur in the boundary layer due to friction and stagnation of the gas mixture initially accelerated behind the leading shock wave generated by the accelerating flame. In the conclusions, they also noted that the case of weak initiation of the DDt in a tube is not possible without the processes which happen in the boundary layer [9,22]. thus, it should be stated that the processes which happen in the turbulent boundary layer are always essential for the DDt in tubes for cases of weak initiation.…”

Section: -D Visualization Of the Ddtmentioning

confidence: 99%

“…Also, Babkin and Kozachenko [7] and Soloukhin [8] conducted experimental visualizations of such processes. Much research on this subject was conducted from that time and detailed descriptions of these processes can be found in [9]. Most of this research was focused on DDt studies in very reactive mixtures, usually in rectangular tubes.…”

Section: Early Research On Ddtmentioning

confidence: 99%

“…this guaranteed high temporal and spatial resolution of the process observed. A detailed description of the test stand and test can be found in [9,21]. they found that just before the DDt, the turbulent flame had a conical structure and that the ignition points, "hot spots", which trigger the DDt are always located at the annular boundary layer 6-35 mm ahead of the cone flame.…”

Section: -D Visualization Of the Ddtmentioning

confidence: 99%

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The Contribution of A. K. Oppenheim to Explaining the Nature of the Initiation of Gaseous Detonation in Tubes

Kuhl

Hayashi

Wolański

2022

Transactions on Aerospace Research

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This paper analyzes A.K. Oppenheim’s original works on the transition of deflagration to detonation and reviews them from the perspective of new numerical and experimental results recently obtained on such phenomena. Particular attention is focused on processes happening in the boundary layer of the tube walls ahead of the accelerating flame. The results of the theoretical analyses of temperature variations inside developing boundary layer are presented and compared to the temperature variation in a free stream away from the boundary layer. Analyses of temperature increase in such layers clearly indicate that the self-ignition of the mixture happens in the boundary layer ahead of the propagating flame front. New experimental results obtained recently by a research group from the A. V. Luikov Heat and Mass Transfer Institute in Minsk, Belarus, combined with previously conducted theoretical analyses and numerical simulations, show clearly and unambiguously that the origin of the “explosion in the explosion”, postulated by A. K. Oppenheim in 1966, is always responsible for the Deflagration-Detonation Transition (DDT) in gases and is located in the boundary layer ahead of the accelerating flame front.

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“…The interaction of flame front and explosion wave resulted in the transition from deflagration to detonation. Krivosheyev et al 28 analyzed the final stage of flame acceleration and the onset of detonation in a cylindrical pipe. Kobiera et al 29 introduced the propagation law of gas cloud explosion in a closed pipeline based on a turbulent combustion rate model.…”

Section: Introductionmentioning

confidence: 99%

Numerical study on over‐pressure performance of premixed explosion in utility tunnel

Xie

Suo

Zhou

et al. 2022

Concurrency and Computation

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The utility tunnel plays a vital role in improving city comprehensive bearing capacity, while whether the gas pipeline is set into the utility tunnel is a focus as chain and coupling accidents will happen in case of fire and explosion. In this study, a scaled-down gas chamber experiment was carried out, and full-scale two-dimensional (2d) and three-dimensional (3d) numerical models were compared. The combustion process of premixed gases could be roughly divided into four development stages, that is, (I) rapid development stage, (II) stable development stage, (III) jump stage, and (IV) oscillation stage. The over-pressure on different walls had the same development trend and the peak value appeared in the jump stage. When the methane-air premixed concentration was 9% and the ignition source was located at the center of utility tunnel (x = 0 m), the most unfavorable working condition occurred as its peak over-pressure was about 1.57 MPa with an increase rate of 70%. Similarly, when the ignition position was at the left end (x = −99 m), the peak over-pressure value was 1.51 MPa, which was 65% more than the initial value. While when the ignition position was not located at the center or ends of utility tunnel, the maximum wall pressure had a "double peaks" characteristic.When x = −80 m, the pressure jumped at 27 and 91 ms with the peak values up to 1.33 and 1.49 MPa, respectively. Arising findings provide guidance for assessing risks of setting the gas pipeline into utility tunnel and help to improve the safety design concept of utility tunnel. K E Y W O R D Scombustion and explosion, numerical simulation, over-pressure, premixed flame, utility tunnel INTRODUCTION BackgroundVarious municipal pipelines, including heating, electricity, water supply, drainage, gas, and communication pipelines can be set into the utility tunnel to construct the underground space of urban roads into a tunnel space. Particularly, gas pipeline is a carrier of natural gas transportation, demonstrating to be significant lifeline projects in cities. However, gas pipelines are susceptible to corrosion, natural disasters, external force excavation, geological changes and so forth which may cause gas leakage, combustion or even explosions. There was a total of 389 gas explosion accidents, and up to 116 accidents were caused by damaged gas pipelines by June 2017. Therefore, the gas pipeline network was expected to be incorporated into the utility tunnel to provide spatial protection, thereby effectively combating various risk factors and facilitating daily operation and maintenance. 1,2 The effect of premixed gas concentration and ignition position on explosion over-pressure needed to be analyzed, and propagation characteristics of explosion shock wave were urgent to be clarified.

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Analysis of the final stage of flame acceleration and the onset of detonation in a cylindrical tube using high-speed stereoscopic imaging

Cited by 30 publications

References 54 publications

Ignition Delay and Reaction Time Measurements of Hydrogen–Air Mixtures at High Temperatures

Ignition Delay and Reaction Time Measurements of Hydrogen–Air Mixtures at High Temperatures

The Contribution of A. K. Oppenheim to Explaining the Nature of the Initiation of Gaseous Detonation in Tubes

Numerical study on over‐pressure performance of premixed explosion in utility tunnel

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