Characteristics of flame propagation in a vortex core: Validity of a model for flame propagation

Asato, Katsuo; Wada, Hidetada; Hiruma, Takayuki; Takeuchi, Yoshitaka

doi:10.1016/s0010-2180(97)00082-5

Cited by 43 publications

(11 citation statements)

References 11 publications

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“…To prevent the induced velocity from diverging, the cut-off radii of the discrete vortex and source, σ and σs, are introduced, and the induced velocities are set to be constant in the cases of σ, σs ≥ |Z − Z j |. 1 and 2 indicate that the summation is performed for the cases of σ, σs < |Z − Z j | and σ, σs ≥ |Z − Z j |, respectively. Movement of the i-th vortex due to the mean convection is performed in the Lagrangian manner after estimating the induced velocity from the complex velocity potential, whereas the Euler method is applied for the integration with respect to the time, as given by the following sets of expressions,…”

Section: Governing Equations or Discrete Vortex Analysis And Source Cmentioning

confidence: 99%

“…Many models for the vortex bursting mechanism have been proposed [1,5,12,20,21,31] based on the active experimental and numerical investigations. However, they have been carried out using a single propagating flame either in a single premixed vortex tube or in a single premixed vortex puff.…”

Section: Introductionmentioning

confidence: 99%

“…However, they have tried to elucidate the hydrodynamic and aerodynamic properties and the large scale vortex structure, and have attached much importance to the mathematical treatment, but not to the practical and applicable viewpoints. There are also many investigations which have tried to simulate the vortex-flame interactions by combining the discrete vortex method with some kinds of flame dynamics [1,4,7,9,11,12,28]. They generally employed the simplified flow and flame configurations, such as an isolated vortex [1,9,28], an opposed diffusion flame [4] and a V-shaped premixed flame [7], but not the practical flow fields, such as jets, wakes and shear flows.…”

Section: Introductionmentioning

confidence: 99%

“…There are also many investigations which have tried to simulate the vortex-flame interactions by combining the discrete vortex method with some kinds of flame dynamics [1,4,7,9,11,12,28]. They generally employed the simplified flow and flame configurations, such as an isolated vortex [1,9,28], an opposed diffusion flame [4] and a V-shaped premixed flame [7], but not the practical flow fields, such as jets, wakes and shear flows. Surprisingly small number of studies could be found so far, which carried out simultaneously the optical analysis and the numerical simulation of the vortex-flame interactions in the practical flow configurations, such as the case of this investigation.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Optical Analysis and Qualitative Discrimination of Vortex-Flame Interaction in a Plane Premixed Shear Layer

Ohiwa

Ishino

2006

Flow Turbulence Combust

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To obtain practical schemes of vortex-flame interactions, a series of organized eddies formed in the plane premixed shear layer is investigated, instead of a single vortex ring or a single vortex tube. The plane premixed shear layer is first formed between two parallel uniform propane-air mixture streams. For getting clear qualitative pictures of vortex-flame interactions in the plane premixed shear layer, two extreme ignition points are assigned; one is assigned at the center of an organized eddy where the vortex motion plays an important role, the other at the midpoint between two adjacent organized eddies where the rolling-up motion prevails. A premixed flame is initiated by an electric discharge at one of the two assigned points and propagates either in the large scale organized eddy or along the interface between two uniform mixture streams. Propagation and deformation processes of the flame are observed using the simultaneously two-directional and high-speed Schlieren photography. The tangential velocity of organized eddy and the equivalence ratio of premixed shear flow are varied as two main parameters. The outline of propagating flame after the midpoint ignition is numerically analyzed by superposing the flame propagation having a constant burning velocity on the vortex flow field simulated with the discrete vortex method. The results obtained show that there exists another type of vortex-flame interaction in the plane shear layer in addition to the vortex bursting, and that it is caused by the rolling-up motion particular to the coherent structure in the plane shear layer and is simply named the vortex boosting. It is qualitatively concluded therefore that, in the ordinary turbulent premixed flames formed in the plane premixed shear layer, these two fundamental N. Ohiwa (B) · Y. Ishino 360 Flow Turbulence Combust (2006) 77: 359-380 vortex-flame interactions get tangled with each other to augment the propagation velocity. An empirical expression which qualitatively takes into account of the effects of both vortex and chemical properties is finally proposed.Key words turbulent premixed flame · plane shear layer · organized eddy · vortex-flame interaction · discrete vortex method · high speed schlieren photography

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Section: Governing Equations or Discrete Vortex Analysis And Source Cmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Optical Analysis and Qualitative Discrimination of Vortex-Flame Interaction in a Plane Premixed Shear Layer

Ohiwa

Ishino

2006

Flow Turbulence Combust

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“…However, the advantages of PDEs, such as their simplicity and low weight, are lost if devices such as a predetonator and an additional igniter are added. To control the DDT distance without using additional ignition energy and adding sophisticated, heavy structures such as a predetonator, efforts have been undertaken to apply the vortex flow (VF) injection concept to the injection part of a PDE, because the flame can propagate very quickly in a VF, depending on the rotation velocity [6][7][8][9][10] . In these studies, the DDT distance was shortened by 15-43%, compared with that of a counterflow injector, when a VF injector was used.…”

Section: Introductionmentioning

confidence: 99%

Characteristics of Flame Propagation in a Vortex Flow for Deflagration-to-Detonation Transition

Asato

Miyasaka

Sukegawa

et al. 2014

AEROSPACE TECHNOLOGY JAPAN

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Behaviors of flame propagation in a detonation tube were observed by the schliren system with a high-speed video camera, and the flow velocity, flame velocity and propagation velocity of the pressure wave and the maximum pressure were measured to clarify the combined effects of a vortex flow on flame propagation and the deflagration-to-detonation transition (DDT) process. The flame is accelerated and the flame velocity is rapidly increased when the Shchelkin spiral is inserted in the tube. The accelerating flame acts as a piston producing the compression wave and it proceeds to the shock, then transition to detonation is accomplished. The DDT distance in the case with the Shchelkin spiral becomes shorter due to the combined effects of a VF and Shchelkin spiral.

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Combined Effects of Vortex Flow and the Shchelkin Spiral Dimensions on Characteristics of Deflagration-to-Detonation Transition

Asato¹,

Miyasaka²,

Watanabe³

et al. 2012

28th International Symposium on Shock Waves

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Characteristics of flame propagation in a vortex core: Validity of a model for flame propagation

Cited by 43 publications

References 11 publications

Optical Analysis and Qualitative Discrimination of Vortex-Flame Interaction in a Plane Premixed Shear Layer

Optical Analysis and Qualitative Discrimination of Vortex-Flame Interaction in a Plane Premixed Shear Layer

Characteristics of Flame Propagation in a Vortex Flow for Deflagration-to-Detonation Transition

Combined Effects of Vortex Flow and the Shchelkin Spiral Dimensions on Characteristics of Deflagration-to-Detonation Transition

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