Experimental investigation of three-dimensional flame-front structure in premixed turbulent combustion

Chen, Yung-Cheng; Bilger, R.W.

doi:10.1016/j.combustflame.2004.04.009

Cited by 69 publications

(20 citation statements)

References 63 publications

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“…2 and Chen and Bilger [18]) and the simulations is the existence of regions of local flame extinction. In this section, we characterize the dynamics of these extinction events.…”

Section: Extinction Events In Hydrogenmentioning

confidence: 83%

Numerical simulation of Lewis number effects on lean premixed turbulent flames

Bell

Cheng

Day

et al. 2007

Proceedings of the Combustion Institute

121

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A dominant factor in determining the burning rate of a premixed turbulent flame is the degree to which the flame front is wrinkled by turbulence. Higher turbulent intensities lead to greater wrinkling of the flame front and an increase in the turbulent burning rate. This picture of turbulent flame dynamics must be modified, however, to accommodate the affects of variations in the local propagation speed of the flame front. Classical flame analysis characterizes these local variations in propagation speed by the Markstein number which represents the response of the flame front to curvature and strain. In this paper, we consider lean premixed flames for three different fuels having widely varying fuel Lewis numbers corresponding to widely varying Markstein numbers. In particular, we present numerical simulations of premixed turbulent flames for lean hydrogen, propane and methane mixtures in two dimensions. Each simulation is performed at turbulence conditions similar to those found in laboratory-scale experiments and is performed using detailed chemical kinetics and transport properties. We discuss the effect of Lewis number on the overall flame morphology and explore the dependence of local flame propagation speed on flame curvature. We also explore the relationship between local flame speed and experimentally accessible variables such as OH concentration. Finally, we focus on the low Lewis number case, hydrogen, in which the flame front is broken indicating local extinction.

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“…2 and Chen and Bilger [18]) and the simulations is the existence of regions of local flame extinction. In this section, we characterize the dynamics of these extinction events.…”

Section: Extinction Events In Hydrogenmentioning

confidence: 83%

Numerical simulation of Lewis number effects on lean premixed turbulent flames

Bell

Cheng

Day

et al. 2007

Proceedings of the Combustion Institute

121

View full text Add to dashboard Cite

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“…These flames do not appear to fit in with flamelet assumptions, as can demonstrated when they are plotted on a flame regime diagram [15]. For Le < 1 mixtures, as u' is increased, localised areas of quench can be identified along with thickening of the reaction zone.…”

Section: Introductionmentioning

confidence: 91%

“…at high values of turbulence the laminar flame structure breaks down as turbulent eddies enter the reaction zone and dissipate heat and species over longer lengths, this ultimately results in flame quench [8]; and (ii) for mixtures with negative Markstein number (or less than unity Lewis number) where lamella like structures (super adiabatic bulge shaped islands) have been observed in turbulent premixed flames [15,16]. These flames do not appear to fit in with flamelet assumptions, as can demonstrated when they are plotted on a flame regime diagram [15].…”

Section: Introductionmentioning

confidence: 99%

The turbulent burning velocity of iso-octane/air mixtures

Lawes

Ormsby

Sheppard

et al. 2012

Combustion and Flame

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Turbulent burning velocities of iso-octane air mixtures have been measured for expanding flame kernels within a turbulent combustion bomb. High speed schlieren images were used to derive turbulent burning velocity. Turbulent velocity measurements were made at u' = 0.5, 1.0, 2.0, 4.0, 6.0 m/s, equivalence ratios of 0.8, 1.0, 1.2, 1.4 and pressures of P = 0.1, 0.5, 1.0 MPa. The turbulent burning velocity was found to increase with time and radius from ignition, this was attributed to turbulent flame development.The turbulent burning velocity increased with increasing rms turbulent velocity, and with pressure; although differences were found in the magnitude of this increase for different turbulent velocities. Generally, raising the equivalence ratio resulted in enhanced turbulent burning velocity, excepting measurements made at the lowest turbulent velocity. The results obtained in this study have been compared with those evaluated for a number turbulent burning velocity correlations and the differences are discussed.2

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“…Lee et al [16,17] observe strong dependence on curvature in the interaction of lean premixed hydrogen flames with Karman vortex streets. Chen and Bilger [18] present data showing cellular structures in a turbulent Bunsen flame and provide detailed scalar measurements of a progress variable, OH and scalar dissipation rate at lean conditions.…”

Section: Introductionmentioning

confidence: 99%