A reaction kernel hypothesis for the stability limit of methane jet diffusion flames

Takahashi, Fumiaki; Katta, Viswanath R.

doi:10.1016/s0082-0784(00)80615-3

Cited by 66 publications

(63 citation statements)

References 17 publications

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“…Takahashi and Katta (21) also investigated the effect of the one-step global chemistry on numerical results in the jet diffusion flames and reported a heat release-rate distribution hooked on the rich side different from the results by the detailed chemistry model and also the present results. However, this result is strongly affected by a rate equation used in their study which overestimates on the rich side than the present one, and does not reflect the scalar field to be evaluated.…”

Section: Resultscontrasting

confidence: 50%

“…The underestimation of the quenching scalar dissipation rate must be caused by intermediate reactions, as reported by Takahashi et al (20) and Takahashi and Katta (21) . Accordingly, we used the rate formula given by Eq.…”

Section: Geometry and Boundary Conditionsmentioning

confidence: 66%

“…Here, the terms are numbered in reference to the order in Eq. (21). A minor unbalance of heat transfer noticed in Fig.…”

Section: Resultsmentioning

confidence: 90%

“…8 (II) comes from the approximations in Eq. (21). For the fully burning counterflow nonpremixed flame, the heat source term (term 6) balances the Z-directional heat diffusion term (term 2).…”

Section: Resultsmentioning

confidence: 99%

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Numerical Investigation of Edge Flame Structure of Counterflow Nonpremixed Flames with Local Extinction Due to Flame Stretch

Noda

Tsubokura

2005

JSME international journal. Ser. B, Fluids and thermal engineer

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Laminar counterflow nonpremixed flames with local extinction caused by nonuniform inflows are numerically investigated in two-dimensions in a system governed by Lewis numbers of unity and assuming a single-step, irreversible, finite-rate reaction. A numerical method based on the SIMPLE algorithm is used. Edge flame structures are investigated through the introduction of a new progress variable defined as the normalized integral of the mass fraction of a product in the mixture fraction Z space and which expresses the progress of the chemical reaction. Calculation results reveal that the edge flame structure can be classified into three regions; fully burning flame, weakened flame with a low reaction rate, and a non-reacting preheat region. Under these conditions, and in terms of the energy balance, the edge flame structure is dependent on the Z-directional heat diffusion transport, heat consumption (given by the progress variable), and heat production by chemical reaction. It is found that each type of flame structure can be well characterized by three parameters; the mixture fraction, the stoichiometric scalar dissipation rate, and the progress variable. These three parameters are identified as important factors affecting the edge flame structure of nonpremixed flames with local extinction.

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Section: Resultscontrasting

confidence: 50%

Section: Geometry and Boundary Conditionsmentioning

confidence: 66%

“…Here, the terms are numbered in reference to the order in Eq. (21). A minor unbalance of heat transfer noticed in Fig.…”

Section: Resultsmentioning

confidence: 90%

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Numerical Investigation of Edge Flame Structure of Counterflow Nonpremixed Flames with Local Extinction Due to Flame Stretch

Noda

Tsubokura

2005

JSME international journal. Ser. B, Fluids and thermal engineer

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“…The mathematical model of the heat and mass transport processes must take numbers of chemical reactions, gas-phase multi-component viscosities, thermal conductivities, diffusion coefficients, thermal diffusion coefficients, thermodynamics and chemical rates into consideration [19][20][21][22][23][24][25][26][27][28][29][30][31]. However, the combination of counterflow diffusion flame and surface ablation of charring materials has never been reported.…”

Section: Introductionmentioning

confidence: 99%

Protection of pyrolysis gases combustion against charring materials’ surface ablation

Huang

Wang

et al. 2016

International Journal of Heat and Mass Transfer

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Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractCharring ablation materials are widely used for thermal protection systems in a vehicle during hypersonic reentry. The pyrolysis gases from the charring materials can react with oxygen in the boundary layer, which makes the surface ablation rate decrease. The problem of protection of combustion of pyrolysis gases in charring material against surface ablation is solved by the detached normal shock wave relations and the counterflow diffusion flame model. The central difference format for the diffusion term and the upwind scheme for the convection term are used to discretize the mathematical model of the counterflow diffusion flame. Numerical results indicate that the combustion of pyrolysis gases in the boundary layer can completely protect the material surface from recession when the velocity of pyrolysis gases injecting to the boundary layer is higher than the critical velocity. There is an allometric relationship between the critical velocity and Mach number, and the combustion heat has little influence on the temperature distribution originating from the aerodynamic heating. This study will be helpful for the design of the thermal protection system in hypersonic reentry vehicles.

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Evaluating the suppression effectiveness of hybrid nitrogen and water mist with a cup burner coflowing flame

Zheng

et al. 2021

Fire and Materials

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A reaction kernel hypothesis for the stability limit of methane jet diffusion flames

Cited by 66 publications

References 17 publications

Numerical Investigation of Edge Flame Structure of Counterflow Nonpremixed Flames with Local Extinction Due to Flame Stretch

Numerical Investigation of Edge Flame Structure of Counterflow Nonpremixed Flames with Local Extinction Due to Flame Stretch

Protection of pyrolysis gases combustion against charring materials’ surface ablation

Evaluating the suppression effectiveness of hybrid nitrogen and water mist with a cup burner coflowing flame

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