Numerical investigation of the mechanism behind the deflagration to detonation transition in homogeneous and inhomogeneous mixtures of H2-air in an obstructed channel

Saeid, Mohammad Hosein Shamsadin; Emami, Sobhan

doi:10.1016/j.ijhydene.2021.04.006

Cited by 47 publications

(4 citation statements)

References 59 publications

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“…Ciccarelli et al [33] conducted experimental studies on the effects of obstacle spacing and BR on the DDT process, finding that obstacle spacing has a huge effect on the DDT distance at high BR and acquires the shortest DDT distance when obstacle spacing is roughly equal to the pipe diameter. Saeid et al [34] studied the spatial height ratio (S/H) of the obstacle spacing to the pipe diameter; they found that in inhomogeneous mixtures, detonation could not be triggered in the tube when the S/H was equal to 10 and that the DDT time was considerably reduced when the S/H was reduced to 2.5. Wang et al [35] investigated the effect of the number of jet obstacles on the DDT process, speculated that there existed an optimal number of jet obstacles, and concluded that the optimal number of jet obstacles may vary with changes in channel size and obstacle spacing.…”

Section: Introductionmentioning

confidence: 99%

Combustion Mechanism of Gasoline Detonation Tube and Coupling of Engine Turbocharging Cycle

Huang,

Wang,

Shi

et al. 2024

Energies

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Traditional exhaust-gas turbocharging exhibits hysteresis under variable working conditions. To achieve rapid-intake supercharging, this study investigates the synergistic coupling process between the detonation and diesel cycles using gasoline as fuel. A numerical simulation model is constructed to analyze the detonation characteristics of a pulse-detonation combustor (PDC), followed by experimental verification. The comprehensive process of the flame’s deflagration-to-detonation transition (DDT) and the formation of the detonation wave are discussed in detail. The airflow velocity, DDT time, and peak pressure of detonation tubes with five different blockage ratios (BR) are analyzed, with the results imported into a one-dimensional GT-POWER engine model. The results indicate that the generation of detonation waves is influenced by flame and compression wave interactions. Increasing the airflow does not shorten the DDT time, whereas increasing the BR causes the DDT time to decrease and then increase. Large BRs affect the initiation speed of detonation in the tube, while small BRs impact the DDT distance and peak pressure. Upon connection to the PDC, the transient response rate of the engine is slightly improved. These results can provide useful guidance for improving the transient response characteristics of engines.

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Section: Introductionmentioning

confidence: 99%

Combustion Mechanism of Gasoline Detonation Tube and Coupling of Engine Turbocharging Cycle

Huang,

Wang,

Shi

et al. 2024

Energies

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“…Saied et al [25] investigated DDT in uniform and stratified mixtures with 15% and 30% hydrogen concentrations. They found that DDT occurred only in stratified conditions in the lean mixture (15% hydrogen).…”

Section: Introductionmentioning

confidence: 99%

Numerical Investigation of the Effects of Diffusion Time on the Mechanisms of Transition from a Turbulent Jet Flame to Detonation in a H2-Air Mixture

Saeid,

Khadem,

Emami

et al. 2023

Fire

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The current study primarily aimed to simulate detonation initiation via turbulent jet flame acceleration in partial-premixed H2-air mixtures. Different vertical concentration gradients were generated by varying the duration of hydrogen injection (diffusion time) within an enclosed channel filled with air. H2-air mixtures with average hydrogen concentrations of 22.5% (lean mixture) and 30% (near stoichiometric mixture) were investigated at diffusion times of 3, 5, and 60 s. Numerical results show that the vertical concentration gradient significantly influences the early stage of flame acceleration (FA). In the stratified lean mixture, detonation began at all the diffusion times, and comparing the flame-speed graphs showed that a decrease in the diffusion time and an increase in the mixture inhomogeneity speeded up the flame propagation and the jet flame-to-detonation transition occurrence in the channel. In the stratified H2-air mixture with an average hydrogen concentration of 30%, the transition from a turbulent jet flame to detonation occurred in all the cases, and the mixture inhomogeneity weakened the FA and delayed the detonation initiation.

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“…There are few studies that evaluate transverse jets to shorten DDT time and length in non-uniform mixtures, and the setup of the jet arrangement, jet pressure, and the required number of jets are rarely reported. There have been some studies on FA [15,16], DDT [17][18][19], and detonation propagation [20][21][22] in non-uniform mixtures with a concentration gradient using a smooth tube or solid-laden chamber. In contrast to homogeneous mixtures, it is revealed that detonation propagation has a more dynamical behavior because of the fuel-lean or fuel-rich impacts [21,23].…”

Section: Introductionmentioning

confidence: 99%

Detonation simulations in supersonic flow under circumstances of injection and mixing

Zhao

Deiterding

Liang

et al. 2023

Proceedings of the Combustion Institute

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Numerical investigation of the mechanism behind the deflagration to detonation transition in homogeneous and inhomogeneous mixtures of H2-air in an obstructed channel

Cited by 47 publications

References 59 publications

Combustion Mechanism of Gasoline Detonation Tube and Coupling of Engine Turbocharging Cycle

Combustion Mechanism of Gasoline Detonation Tube and Coupling of Engine Turbocharging Cycle

Numerical Investigation of the Effects of Diffusion Time on the Mechanisms of Transition from a Turbulent Jet Flame to Detonation in a H2-Air Mixture

Detonation simulations in supersonic flow under circumstances of injection and mixing

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