Soot formation characteristics of gasoline surrogate fuels in counterflow diffusion flames

Soot generally refers to carbonaceous particles formed during incomplete combustion of hydrocarbon fuels. A typical simulation of soot formation and evolution contains two parts: gas chemical kinetics, which models the chemical reaction from hydrocarbon fuels to soot precursors, that is, polycyclic aromatic hydrocarbons or PAHs, and soot dynamics, which models the soot formation from PAHs and evolution due to gas-soot and soot-soot interactions. In this study, two detailed gas kinetic mechanisms (ABF and KM2) have been compared during the simulation (using the solver Chemkin II) of ethylene combustion in counterflow diffusion flames. Subsequently, the operator splitting Monte Carlo method is used to simulate the soot dynamics. Both the simulated data from the two mechanisms for gas and soot particles are compared with experimental data available in the literature. It is found that both mechanisms predict similar profiles for the gas temperature and velocity, agreeing well with measurements. However, KM2 mechanism provides much closer prediction compared to measurements for soot gas precursors. Furthermore, KM2 also shows much better predictions for soot number density and volume fraction than ABF. The effect of nozzle exit velocity on soot dynamics has also been investigated. Higher nozzle exit velocity renders shorter residence time for soot particles, which reduces the soot number density and volume fraction accordingly.

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The Effect of the Strain Rate on PAH/Soot Formation in Laminar Counterflow Diffusion Flames

Combustion Science and Technology ◽

10.1080/00102200903236142 ◽

2010 ◽

Vol 182 (2) ◽

pp. 103-123 ◽

Cited By ~ 6

Author(s):

V. Huijnen ◽

A. V. Evlampiev ◽

L. M. T. Somers ◽

R. S. G. Baert ◽

L. P. H. de Goey

Keyword(s):

Strain Rate ◽

Diffusion Flames ◽

Soot Formation ◽

Counterflow Diffusion Flames

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Fuel Oxygen Effects on Soot Formation in Counterflow Diffusion Flames

Combustion Science and Technology ◽

10.1080/00102208708947016 ◽

1987 ◽

Vol 53 (1) ◽

pp. 1-21 ◽

Cited By ~ 42

Author(s):

H. S. Hura ◽

I. Glassman

Keyword(s):

Diffusion Flames ◽

Soot Formation ◽

Counterflow Diffusion Flames ◽

Oxygen Effects

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Experimental and Numerical Study on the Sooting Behaviors of Furanic Biofuels in Laminar Counterflow Diffusion Flames

Energies ◽

10.3390/en14185995 ◽

2021 ◽

Vol 14 (18) ◽

pp. 5995

Author(s):

Qianqian Mu ◽

Fuwu Yan ◽

Jizhou Zhang ◽

Lei Xu ◽

Yu Wang

Keyword(s):

Volume Fraction ◽

Diffusion Flames ◽

Soot Formation ◽

Numerical Study ◽

Soot Volume Fraction ◽

Special Focus ◽

Counterflow Diffusion Flames ◽

C3 Species ◽

Polycyclic Aromatic ◽

Counterflow Flames

Furanic biofuels have received increasing research interest over recent years, due to their potential in reducing greenhouse gas emissions and mitigating the production of harmful pollutants. Nevertheless, the heterocyclic structure in furans make them readily to produce soot, which requires an in-depth understanding. In this study, the sooting characteristic of several typical furanic biofuels, i.e., furan, 2-methylfuran (MF), and 2,5-dimethylfuran (DMF), were investigated in laminar counterflow flames. Combined laser-based soot measurements with numerical analysis were performed. Special focus was put on understanding how the fuel structure of furans could affect soot formation. The results show that furan has the lowest soot volume fraction, followed by DMF, while MF has the largest value. Kinetic analyses revealed that the decomposition of MF produces high amounts of C3 species, which are efficient benzene precursors. This may be the reason for the enhanced formation of polycyclic aromatic hydrocarbons (PAHs) and soot in MF flames, as compared to DMF and furan flames. The major objectives of this work are to: (1) understand the sooting behavior of furanic fuels in counterflow flames, (2) elucidate the fuel structure effects of furans on soot formation, and (3) provide database of quantitative soot concentration for model validation and refinements.

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