Edge flame instability in low-strain-rate counterflow diffusion flames

Park, June Sung; Hwang, Dong-Jin; Park, Jeong; Kim, Jeong Soo; Kim, Sungcho; Keel, Sang In; Kim, Tae Kwon; Noh, Dong Soon

doi:10.1016/j.combustflame.2006.06.009

Cited by 37 publications

(16 citation statements)

References 25 publications

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“…It has been found that non-unity Lewis number has significant effects on the edge flame propagation as indicated by several previous analytical studies, and the interested readers are referred to the review paper by Buckmaster [47] and references therein for the main findings. Recent experimental studies by Takita et al [48,49], Park et al [50], Cha and Rooney [51] addressed different aspects of differential diffusion due to non-unity Lewis number on the overall burning characteristics and edge flame propagation. Cho and Takita [52] numerically studied the effects on non-unity Lewis number on edge flames in a counter-flow configuration.…”

Section: Introductionmentioning

confidence: 99%

Effects of Fuel Lewis Number on Localised Forced Ignition of Turbulent Mixing Layers

Chakraborty

Hesse

Mastorakos

2009

Flow Turbulence Combust

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The influences of fuel Lewis number Le F on localised forced ignition of inhomogeneous mixtures are analysed using three-dimensional compressible Direct Numerical Simulations (DNS) of turbulent mixing layers for Le F = 0.8, 1.0 and 1.2 and a range of different root-mean-square turbulent velocity fluctuation u values. For all Le F cases a tribrachial flame has been observed in case of successful ignition. However, the lean premixed branch tends to merge with the diffusion flame on the stoichiometric mixture fraction isosurface at later stages of the flame evolution. It has been observed that the maximum values of temperature and reaction rate increase with decreasing Le F during the period of external energy addition. Moreover, Le F is found to have a significant effect on the behaviours of mean temperature and fuel reaction rate magnitude conditional on mixture fraction values. It is also found that reaction rate and mixture fraction gradient magnitude |∇ξ | are negatively correlated at the most reactive region for all values of Le F explored. The probability of finding high values of |∇ξ | increases with increasing Le F . For a given value of u , the extent of burning decreases with increasing Le F . A moderate increase in u gives rise to an increase in the extent of burning for Le F = 0.8 and 1.0, which starts to decrease with further increases in u . For Le F = 1.2, the extent of burning decreases monotonically with increasing u . The extent of edge flame propagation on the stoichiometric mixture fraction ξ = ξ st isosurface is characterised by the probability of finding burned gas on this isosurface, which decreases with increasing u and Le F . It has been found that it is easier to obtain self-sustained combustion following localised forced ignition in case of inhomogeneous mixtures than that in the case 126 Flow Turbulence Combust (2010) 84:125-166 of homogeneous mixtures with the same energy input, energy deposition duration when the ignition centre is placed at the stoichiometric mixture. The difficultly to sustain combustion unaided by external energy addition in homogeneous mixture is particularly prevalent in the case of Le F = 1.2.

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Section: Introductionmentioning

confidence: 99%

Effects of Fuel Lewis Number on Localised Forced Ignition of Turbulent Mixing Layers

Chakraborty

Hesse

Mastorakos

2009

Flow Turbulence Combust

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“…Thus, its experimental results have been mostly obtained through micro-gravity experiments [8]. Some of the distinguishing phenomena involved in mesoscale combustion are as follows: (1) the HSR extinction limit relates to burner configuration and the kinematic viscosities of flows, (2) the LSR extinction limit can be explained by combining the two theories of non-premixed flame stretch and premixed flame quenching, and (3) flame oscillation occurs near LSR extinction limits, as in studies conducted in open spaces [9].…”

Section: Introductionmentioning

confidence: 99%

Characteristics of opposed flow partially premixed flames in mesoscale channels at low strain rates

Lee

Cho

Kim

2015

Proceedings of the Combustion Institute

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“…In Ref. [6], experiments in low-strainrate methane-air counterflow diffusion flames diluted with nitrogen have been conducted to study flame extinction behavior and edge flame oscillation.…”

Section: Introductionmentioning

confidence: 99%

Theoretical Analysis of Diffusion Flames Using Perturbation Method for Different Lewis and Damkohler Numbers

2013

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This paper presents a two dimensional asymptotic model of counterflow diffusion flame in the presence of radiation heat loss. The fuel and oxidizer, respectively, are injected from left and right hand side of the flame. The effects of burning rate, Lewis and Damkohler number on the structure and extinction of the flame is studied using perturbation method. To do so, the structure of the flame is considered to be composed of reaction zone with a thickness of O(ε) and radiation heat loss zone, of O(δ) thickness, that sandwiches the reaction zone. The effect of burning rate is illustrated by burning pre-exponential parameter, B. It is found that with the increase of the parameter, the flame temperature is also increased, and flame location moves toward the fuel side. In addition, the variation of Lewis number of fuel and oxidizer has a significant effect on the location and temperature of the flame.

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Edge flame instability in low-strain-rate counterflow diffusion flames

Cited by 37 publications

References 25 publications

Effects of Fuel Lewis Number on Localised Forced Ignition of Turbulent Mixing Layers

Effects of Fuel Lewis Number on Localised Forced Ignition of Turbulent Mixing Layers

Characteristics of opposed flow partially premixed flames in mesoscale channels at low strain rates

Theoretical Analysis of Diffusion Flames Using Perturbation Method for Different Lewis and Damkohler Numbers

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