Adaptive simulations of flame acceleration and detonation transition in subsonic and supersonic mixtures

Zhao, Wandong; Deiterding, Ralf; Liang, Jianhan; Wang, Xinxin; Cai, Xiaodong; Duell, Jon

doi:10.1016/j.ast.2023.108205

Cited by 8 publications

(2 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With the passage of time, this hot spot leads to a local explosion, causing an overdriven detonation wave to form. This result is similar to the mechanism of local detonation initiation caused by the pressure buildup at the leading edge of the flame, as observed by Zhao et al [44].…”

Section: Effects Of Inhomogeneity On Fa and Ddt In Stoichiometric Mix...supporting

confidence: 90%

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

View full text Add to dashboard Cite

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.

show abstract

Section: Effects Of Inhomogeneity On Fa and Ddt In Stoichiometric Mix...supporting

confidence: 90%

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

View full text Add to dashboard Cite

show abstract

“…In this study, we rely on the engine fuel supply system to inject high-pressure fuel directly into the detonation tube so that the fuel is rapidly broken and atomized into tiny particles (particle size < 8.5 µm), which substantially simplifies the multiphysical process of liquid fuel in the volatilization process. For numerical simulation, Energies 2024, 17, 2466 3 of 16 most studies have utilized two-dimensional (2D) simulation to reduce the computation time [45][46][47]; however, in the study of two-phase detonation, the mixing, atomization, and evaporation process of liquid fuel is the key to the formation of combustible mixtures. Computational fluid dynamics (CFD) can simulate the whole process of fuel from injection to mixing with the oxidant, which can provide a comprehensive understanding of how the three-dimensional (3D) detonation structure evolves so as to better optimize the detonation and combustion process.…”

Section: Introductionmentioning

confidence: 99%

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

Huang,

Wang,

Shi

et al. 2024

Energies

View full text Add to dashboard Cite

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.

show abstract

Influence of aerodynamic valve structural parameters on detonation initiation and back pressure characteristics of air-breathing pulse detonation engine

Wang,

Zheng,

Yang

et al. 2024

Aerospace Science and Technology

View full text Add to dashboard Cite

Adaptive simulations of flame acceleration and detonation transition in subsonic and supersonic mixtures

Cited by 8 publications

References 60 publications

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

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

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

Influence of aerodynamic valve structural parameters on detonation initiation and back pressure characteristics of air-breathing pulse detonation engine

Contact Info

Product

Resources

About