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Diffusion flame

About: Diffusion flame is a research topic. Over the lifetime, 9266 publications have been published within this topic receiving 233522 citations.


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Journal ArticleDOI
TL;DR: In this article, a chemical-kinetic mechanism is presented for autoignition, deflagration, detonation, and diffusion flames of a number of different fuels. But the mechanism is restricted to pressures below about 100 atm, temperatures above about 1000 K, and equivalence ratios less than about 3 for premixed systems, thereby excluding soot formation and low-temperature fuel-peroxide chemistry.

156 citations

Journal ArticleDOI
TL;DR: In this paper, a mixture fraction approach was used to measure the volume fraction of a turbulent ethylene diffusion flame and compared with predictions, and the results showed that in the lower parts of the flame this formulation is not adequate.
Abstract: Soot volume fraction measurements are made in turbulent ethylene diffusion flames and are compared with predictions. The theoretical model is based on mixture fraction distributions in the flame and measured soot volume fractions are correlated against predicted mixture fraction. The results show that in the lower parts of the flame this formulation is not adequate. However, the maximum soot concentrations further up the flame are less dependent on residence time and a mixture fraction approach may be useful here.

156 citations

Journal ArticleDOI
TL;DR: In this article, the authors describe a mechanism for the stabilization of ultra lean premixed methane/air flames by pulsed nonequilibrium plasma enhancement and demonstrate that the pulsed discharge plasma produces a cool stream of relatively stable intermediate species including hydrogen (H{sub 2}) and carbon monoxide (CO), which play a central role in enhancing flame stability.

156 citations

Journal ArticleDOI
01 Jan 2011
TL;DR: In this paper, a direct numerical simulation of the near field of a three-dimensional spatially developing turbulent ethylene jet flame in highly-heated coflow is performed with a reduced mechanism to determine the stabilization mechanism.
Abstract: Direct numerical simulation (DNS) of the near-field of a three-dimensional spatially-developing turbulent ethylene jet flame in highly-heated coflow is performed with a reduced mechanism to determine the stabilization mechanism. The DNS was performed at a jet Reynolds number of 10,000 with over 1.29 billion grid points. The results show that auto-ignition in a fuel-lean mixture at the flame base is the main source of stabilization of the lifted jet flame. The Damko¨ hler number and chemical explosive mode (CEM) analysis also verify that auto-ignition occurs at the flame base. In addition to auto-ignition, Lagrangian tracking of the flame base reveals the passage of large-scale flow structures and their correlation with the fluctuations of the flame base similar to a previous study (Yoo et al., J. Fluid Mech. 640 (2009) 53–481) with hydrogen/air jet flames. It is also observed that the present lifted flame base exhibits a cyclic ‘saw-tooth’ shaped movement marked by rapid movement upstream and slower movement downstream. This is a consequence of the lifted flame being stabilized by a balance between consecutive auto-ignition events in hot fuel-lean mixtures and convection induced by the high-speed jet and coflow velocities. This is confirmed by Lagrangian tracking of key variables including the flame-normal velocity, displacement speed, scalar dissipation rate, and mixture fraction at the stabilization point.

154 citations

Journal ArticleDOI
01 Jan 2007
TL;DR: In this paper, the effect of the FAME molecular structure on combustion chemistry was studied in an opposed flow diffusion flame and a jet stirred reactor, and the experimental results showed that methyl crotonate combustion produces much higher levels of C 2 H 2, 1-C 3 H 4, 1 -C 4 H 8, and 1,3-C 4H 6 than methyl butanoate.
Abstract: Biodiesel fuels, made up primarily of fatty acid methyl esters (FAME), are advantageous because they are renewable and generally have lower pollutant emissions. In order to study in detail the effect of the FAME molecular structure on the combustion chemistry, a saturated (i.e., methyl butanoate) and an unsaturated (i.e., methyl crotonate) C 4 FAME were oxidized in an opposed flow diffusion flame and a jet stirred reactor. Some consistent trends were seen in both experiments. Both fuels have similar reactivity. The experimental results show that methyl crotonate combustion produces much higher levels of C 2 H 2 , 1-C 3 H 4 , 1-C 4 H 8 , and 1,3-C 4 H 6 than methyl butanoate. The methyl butanoate combustion had higher levels of C 2 H 4 . In the opposed flow diffusion flames, the methyl crotonate also produced benzene while for methyl butanoate it was not detected. These species are relevant to soot formation. In addition, the experiments measured higher levels of 2-propenal, methanol, and acetaldehyde for methyl crotonate than for methyl butanoate. The reactions controlling these differences are discussed.

154 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023183
2022331
2021194
2020133
2019141
2018157