Effects of Soret diffusion on spherical flame initiation and propagation

Han, Wang; Chen, Zheng

doi:10.1016/j.ijheatmasstransfer.2014.11.062

Cited by 18 publications

(14 citation statements)

References 44 publications

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“…It is noted that the extinction strain rate is highly sensitive to the variations in the diffusive properties. The presence of Soret diffusion can decrease/increase the effective Lewis numbers of light/heavy fuels (Han and Chen, 2015). Therefore, it is expected that Soret diffusion can have a relatively strong influence on the extinction strain rate for flames containing sufficiently light/heavy fuels.…”

Section: Resultsmentioning

confidence: 99%

Effects of Soret Diffusion on Premixed Counterflow Flames

Han

Chen

2015

Combustion Science and Technology

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Soret diffusion is a secondary mass diffusion and it affects laminar flames with very lightor heavy species and large temperature gradients. To get a general understanding of Soret effects on stretched flames, we conduct theoretical analysis on a premixed counterflow flame with Soret diffusion. A deliberately idealized premixed counterflow flame model is analyzed asymptotically within the framework of large activation energy, potential flow, and thermal-diffusive model. A correlation among flame stretch rate, flame position, and flame temperature is derived and is used to assess the effects of Soret diffusion on counterflow flame structure, Markstein length, and extinction stretch rate. Results show that Soret diffusion quantitatively affects the premixed counterflow flame and that the influence of Soret diffusion strongly depends on Lewis number and stretch rate. For light fuels, the premixed counterflow flame becomes stronger after including Soret diffusion. The opposite trend occurs for heavy fuels. The influence of Soret diffusion is found to increase with the stretch rate. A linear change between normalized Markstein length and Soret diffusion coefficient is observed, indicating that flame becomes more sensitive to stretch rate after including Soret diffusion. Furthermore, Soret diffusion is shown to greatly increase the extinction stretch rate of light fuels. These results indicate that for highly-stretched premixed flames containing very light species, the impact of Soret diffusion cannot be neglected.

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Section: Resultsmentioning

confidence: 99%

Effects of Soret Diffusion on Premixed Counterflow Flames

Han

Chen

2015

Combustion Science and Technology

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“…Law [22] pointed out that the Soret diffusion (mass diffusion due to temperature gradient) is generally much smaller than the Fickian diffusion (mass diffusion due to concentration gradient), except for very light species (such as H and H 2 ) and heavy species (such as particle and soot) [23][24][25][26] . Therefore, the Soret diffusion is usually neglected including in micro-and meso-scale combustions of CH 4 [27] .…”

Section: Mathematical Modelmentioning

confidence: 99%

Effect of the length of a plate flame holder on flame blowout limit in a micro-combustor with preheating channels

Wan

Fan

Yao

2016

Combustion and Flame

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“…The governing equations (4) are solved in a sufficiently large rectangular coordinate region with the boundary conditions similar to (6), where ξ is replaced with x, imposed at the edges of the space grid along the y axis and zero flux conditions for θ , y A , and y R for the edges along the x axis. The length of the region along the x direction is chosen to be sufficiently large so that the boundary conditions (6) are satisfied with reasonable accuracy.…”

Section: Pulsating and Cellular Wavesmentioning

confidence: 99%

“…It is known that such processes as Soret diffusion [2][3][4][5][6][7][8], radical-wall interaction [9][10][11][12][13][14][15][16][17], adding of flame inhibitors/flame suppressants [18,19] can affect the concentration of radicals in the In hydrocarbon flames the inclusion of Soret diffusion affects the mass fluxes of light components of reacting mixtures, mainly, H and H 2 [2][3][4][5][6][7]. In freely propagating flames it is sufficient to consider the thermal diffusion of H radicals, which causes the additional flux of H atoms in the downstream direction.…”

Section: Introductionmentioning

confidence: 99%

The effect of depletion of radicals on freely propagating hydrocarbon flames

et al. 2015

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In this work we investigate the properties and stability of deflagration waves in the model which include the two-step chain-branching reaction mechanism, first order reaction of conversion of radicals into products, and Newtonian cooling to the surroundings. The propagation velocity, the maximum temperature and concentration of radicals monotonically decay as the rate of the radical termination reaction is increased. The critical parameter values for the onset of instabilities and quenching of the travelling combustion wave are found. It is demonstrated that the depletion of radicals through the additional termination reaction enhances the onset of instabilities and extinction. The comparison of the efficiency of the radical and thermal quenching mechanisms is performed. The solutions emerging once the travelling deflagration wave becomes unstable are studied.

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Effects of Soret diffusion on spherical flame initiation and propagation

Cited by 18 publications

References 44 publications

Effects of Soret Diffusion on Premixed Counterflow Flames

Effects of Soret Diffusion on Premixed Counterflow Flames

Effect of the length of a plate flame holder on flame blowout limit in a micro-combustor with preheating channels

The effect of depletion of radicals on freely propagating hydrocarbon flames

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