Results 251 to 260 of about 128,331 (304)

Thick Flames with Localised Heat Loss

Combustion Science and Technology, 1990
Abstract The solution of the one-dimensional premixed flame equations is considered with Arrhenius kinetics, not only with the assumption of large activation energy, but also large heat release. Previous studies have shown that under these circumstances, the chemical zone widens considerably with the pre-heat zone no longer able to be modelled as a ...
A. C MclNTOSH, C. KAAS-PETERSEN
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Thermoacoustical noise induced by laminar flame annihilation at varying flame thicknesses

18th AIAA/CEAS Aeroacoustics Conference (33rd AIAA Aeroacoustics Conference), 2012
The thermoacoustic response of a harmonically excited laminar lean-premixed flame is investigated with respect to artificially increased flame thicknesses. The flame dynamics is described by solutions of the Navier-Stokes equations plus a combined G-equation progress variable modeling approach based on an unstructured Cartesian method.
G. Geiser, S. Schlimpert, Wolfgang Schröder   +2 more
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Implications of laminar flame finite thickness on the structure of turbulent premixed flames

Journal of Fluid Mechanics, 2015
A layered description of the structure of turbulent flame brushes is provided for situations featuring large but finite values of the Damköhler number, which correspond to the wrinkled flame regime of turbulent premixed combustion. One special focus of this study is placed on the description of the leading edge of the turbulent flame brush, the role of
Kha, Kim Q. N., Robin, Vincent, Mura, Arnaud, Champion, Michel   +3 more
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Finite flame thickness effects on Kolmogorov-Petrovsky-Piskunov turbulent burning velocities

Physical Review E, 2022
KPP (Kolmogorov-Petrovsky-Piskunov) solutions of the reaction-diffusion equation have application in various physical phenomena occurring in biology, ecology, and reacting flows. In particular, these solutions are commonly used in turbulent combustion to scale turbulent burning velocities.
Sukruth Somappa, Vishal Acharya, Tim Lieuwen   +2 more
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The thickness of laminar flames

Combustion and Flame, 1984
The thickness of a combustion flame is modeled numerically on the basis of the energy equation. Consideration is limited to a steady-state one-dimensional laminar flame. Calculations are presented for the thickness of a pure thermal flame and air-methane, air-propane, and air-hydrogen flames.
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Flame characteristics of turbulent lean premixed methane/air flames at high pressure: Turbulent flame speed and flame brush thickness

Proceedings of the Combustion Institute, 2007
Abstract The effects of operating conditions and turbulence on flame front position, turbulent flame speed and flame brush thickness of lean premixed methane/air flames at high pressure are investigated experimentally. A comparison of the measured turbulent flame speeds with existing correlations is presented and discussed.
P. Griebel, P. Siewert, P. Jansohn
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Wind-aided flame spread over thick solids

Combustion and Flame, 1991
Abstract This study theoretically analyzes flame spread over thick solid fuels (noncharring) in concurrent oxidizer flows. Emphasis is placed on making rationally justifiable physical approximations that produce useful results. It is discovered that by making only one additional assumption (steady pyrolysis zone) over that of the previous analysis of
Indrek S. Wichman, Sanjay Agrawal
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The thick flame asymptotic limit and Damköhler's hypothesis

Combustion Theory and Modelling, 2002
We derive analytical expressions for the burning rate of a flame propagating in a prescribed steady parallel flow whose scale is much smaller than the laminar flame thickness. In this specific context, the asymptotic results can be viewed as an analytical test of Damkoḧler's hypothesis relating to the influence of the small scales in the flow on the ...
Daou, J., Dold, J., Matalon, M.
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Quiescent flame spread over thick fuels in microgravity

Symposium (International) on Combustion, 1996
Experimental results for flame spread over thick PMMA in microgravity are reviewed. The results were obtained abouard three different space shuttle missions, STS-54, STS-63, and STS-64. For the three conditions, 50% O 2 in N 2 at 1 atm, 50% O 2 at 2 atm, and 70% O 2 at 1 atm, the flame-spread rate slowly decreases with time, which varied from about
Jeff West, Lin Tang, Robert A. Altenkirch, Subrata Bhattacharjee, Kurt Sacksteder, Michael A. Delichatsions   +5 more
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Ignitor and Thickness Effects on Upward Flame Spread

Fire Technology, 1998
The effects of a material's ignitor characteristics and burning duration on upward wall flame spread are investigated. The ignitor is represented as an energy line source. Its energy release rate and its duration after ignition are considered. The material is represented as a finite, thick noncharring material with properties representative of ...
J. Q. Quintiere, C. H. Lee
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