Hydrogen addition to acetylene–air laminar diffusion flames: Studies on soot formation under different flow arrangements

2007 ◽  
Vol 148 (4) ◽  
pp. 249-262 ◽  
Author(s):  
P PANDEY ◽  
B PUNDIR ◽  
P PANIGRAHI
Keyword(s):  
Diffusion Flames ◽  
Soot Formation ◽  
Laminar Diffusion Flames ◽  
Hydrogen Addition ◽  
Laminar Diffusion

scholarly journals The influence of aliphatics on soot inception modelling

2021 ◽  
Author(s):  
Nemanja Ceranic
Keyword(s):  
Volume Fraction ◽  
Diffusion Flames ◽  
Soot Formation ◽  
Fluid Dynamic ◽  
Soot Volume Fraction ◽  
Surface Reactivity ◽  
Complex Nature ◽  
Laminar Diffusion Flames ◽  
Laminar Diffusion ◽  
Polycyclic Aromatic

Soot models have been investigated for several decades and many fundamental models exist that prescribe soot formation in agreement with experiments and theories. However, due to the complex nature of soot formation, not all pathways have been fully characterized. This work has numerically studied the influence that aliphatic based inception models have on soot formation for coflow laminar diffusion flames. CoFlame is the in-house parallelized FORTRAN code that was used to conduct this research. It solves the combustion fluid dynamic conservation equations for a variety of coflow laminar diffusion flames. New soot inception models have been developed for specific aliphatics in conjunction with polycyclic aromatic hydrocarbon based inception. The purpose of these models was not to be completely fundamental in nature, but more so a proof-of-concept in that an aliphatic based mechanism could account for soot formation deficiencies that exist with just PAH based inception. The aliphatic based inception models show potential to enhance predicative capability by increasing the prediction of the soot volume fraction along the centerline without degrading the prediction along the pathline of maximum soot. Additionally, the surface reactivity that was used to achieve these results lied closer in the range of numerically derived optimal values as compared to the surface reactivity that was needed to match peak soot concentrations without the aliphatic based inception models.

Influence of Pressure on Soot Formation in Laminar Diffusion Flames of Methane

2005 ◽  
Author(s):  
Omer Gulder ◽  
Kevin Thomson ◽  
Elizabeth Weckman ◽  
Roydon Fraser ◽  
Greg Smallwood ◽  
...  
Keyword(s):  
Diffusion Flames ◽  
Soot Formation ◽  
Laminar Diffusion Flames ◽  
Laminar Diffusion

scholarly journals A Numerical Investigation on Soot Formation From Laminar Diffusion Flames of Ethylene/Methane Mixture

2008 ◽  
Author(s):  
Hongsheng Guo ◽  
Stephanie Trottier ◽  
Matthew R. Johnson ◽  
Gregory J. Smallwood
Keyword(s):  
Volume Fraction ◽  
Diffusion Flames ◽  
Soot Formation ◽  
Soot Volume Fraction ◽  
Fuel Mixture ◽  
Methyl Radical ◽  
Laminar Diffusion Flames ◽  
Laminar Diffusion ◽  
Methane Mixture ◽  
Phase Chemistry

The sooting propensity of laminar diffusion flames employing ethylene/methane mixture fuel is investigated by numerical simulation. Detailed gas phase chemistry and moments method are used to describe the chemical reaction process and soot particle dynamics, respectively. The numerical model captures the primary features experimentally observed previously. At constant temperatures of air and fuel mixture, both maximum soot volume fraction and soot yield monotonically decrease with increasing the fraction of carbon from methane in the fuel mixture. However, when the temperatures of air and fuel mixture are preheated so that the adiabatic temperatures of all flames are same, the variation of the maximum soot yield becomes higher than what would be expected from a linear combination of the flames of pure ethylene and pure methane, showing a synergistic phenomenon in soot formation. Further analysis of the details of the numerical results suggests that the synergistic phenomenon is caused by the combined effects of the variations in the concentrations of acetylene (C2H2) and methyl radical (CH3). When the fraction of carbon from methane in fuel mixture increases, the concentration of C2H2 monotonically decreases, whereas that of methyl radical increases, resulting in a synergistic phenomenon in the variation of propargyl (C3H3) radical concentration due to the reactions C2H2 + CH3 = PC3H4 + H and PC3H4 + H = C3H3 + H2. This synergistic phenomenon causes a qualitatively similar variation trend in the concentration of pyrene (A4) owing to the reaction paths C3H3 → A1 (benzene) → A2 (naphthalene) → A3 (phenanthrene) → A4. Consequently, the synergistic effect occurs for soot inception and PAH condensation rates, leading to the synergistic phenomenon in soot yield. The similar synergistic phenomenon is not observed in the variation of peak soot volume fraction, since the maximum surface growth rate monotonically decreases, as the fraction of carbon from methane in fuel mixture increases.

Relative effect of acetylene and PAHs addition on soot formation in laminar diffusion flames of methane with oxygen and oxygen-enriched air

2000 ◽  
Vol 122 (1-2) ◽  
pp. 76-89 ◽  
Author(s):  
Sergei A. Zelepouga ◽  
Alexei V. Saveliev ◽  
Lawrence A. Kennedy ◽  
Alexander A. Fridman
Keyword(s):  
Diffusion Flames ◽  
Soot Formation ◽  
Relative Effect ◽  
Laminar Diffusion Flames ◽  
Laminar Diffusion
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