Numerical investigation of self-sustaining modes of 2D planar detonations under concentration gradients in hydrogen–oxygen mixtures

Song, Qingguan; Han, Yong; Cao, Wei

doi:10.1016/j.ijhydene.2020.08.014

Cited by 11 publications

(4 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because of the continuous reaction profile of the one-step model, the detonation cannot be quenched if the growth time is long enough. 30 In the next step, a detailed chemical reaction kinetic model will be adopted to simulate the detonation in non-uniform supersonic flow. The fluctuation of the detonation front caused by velocity layers may be reasonably assumed as reducing the pressure oscillations caused by the rapid combustion of unburned pockets to promote the propagation of the detonation wave.…”

Section: Effects Of Velocity Shear Layermentioning

confidence: 99%

“…The uneven distribution of flow parameters has been found to considerably influence the detonation wave propagation. [27][28][29] Song et al 30 numerically studied self-sustaining modes of detonations in inhomogeneous mixtures of hydrogen and oxygen. They 30 found that there are different self-sustaining detonation modes at low, medium, and high concentration gradients.…”

Section: Introductionmentioning

confidence: 99%

“…[27][28][29] Song et al 30 numerically studied self-sustaining modes of detonations in inhomogeneous mixtures of hydrogen and oxygen. They 30 found that there are different self-sustaining detonation modes at low, medium, and high concentration gradients. Kuznetsov et al 31 indicated that the detonation behaviours influenced by the concentration gradient mainly depends on the gradient sharpness.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of velocity shear layer on detonation propagation in a supersonic expanding combustor

Cai

Mahmoudi

2021

Physics of Fluids

View full text Add to dashboard Cite

This study investigates the mechanism of detonation propagation in a stoichiometric hydrogen-oxygen mixture with non-uniform flow velocity entering an expanding combustor. For simulation of the detonation propagation, the Navier-Stokes equations with a one-step two-species chemistry model are solved by employing the hybrid sixth-order weighted essentially non-oscillatory centre difference scheme. The self-sustaining mechanism of detonation propagation in an expanding combustor under the action of non-uniform supersonic flow with a velocity shear layer is revealed. The results show that under the influence of velocity shear layer, two different unburned jets are produced behind the detonation front. These jets are induced by the velocity shear layers and the Prandtl-Meyer expansion fan. The two jets interact and mix gradually. The interaction between the mixed unburned jets and highly unstable shear layers creates large-scale vortices that intensify the turbulent mixing of the unburned jets. Meanwhile, the baroclinic mechanism generates numerous vortices on the boundary of the unburned jet. These vortices promote the mixing of the burned and unburned gases, which eventually leads to the rapid consumption of the unburned pockets. The heat released due to the burning of the unreacted pockets behind the detonation wave, supports a self-sustaining propagation of the detonation wave. When the velocity difference among the shear layers increases, the surface fluctuation of the detonation wave increases.

show abstract

Section: Effects Of Velocity Shear Layermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of velocity shear layer on detonation propagation in a supersonic expanding combustor

Cai

Mahmoudi

2021

Physics of Fluids

View full text Add to dashboard Cite

show abstract

“…Also, they showed that the concentration at the ignition source significantly influences flame development. Song et al [24] conducted numerical investigations into self-sustaining detonation modes within heterogeneous hydrogen-oxygen mixtures. They observed that concentration gradients were pivotal in alternating between multi-head and single-head detonation modes.…”

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

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

Numerical Investigation of the Influence of Fuel Concentration Gradient on Propane/Oxygen Detonation Propagation

Shao,

Wu,

Meng

et al. 2023

J. Therm. Sci.

View full text Add to dashboard Cite

Numerical investigation of self-sustaining modes of 2D planar detonations under concentration gradients in hydrogen–oxygen mixtures

Cited by 11 publications

References 45 publications

Effects of velocity shear layer on detonation propagation in a supersonic expanding combustor

Effects of velocity shear layer on detonation propagation in a supersonic expanding combustor

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 Influence of Fuel Concentration Gradient on Propane/Oxygen Detonation Propagation

Contact Info

Product

Resources

About