Soot Formation in Propane/Air Diffusion Flames

2013 ◽  
Vol 668 ◽  
pp. 123-127 ◽  
Author(s):  
Xue Sun ◽  
D.W. Zhang ◽  
G.L. Ning
Keyword(s):  
Particle Size ◽  
Soot Particle ◽  
Rate Coefficient ◽  
Diffusion Flames ◽  
Soot Formation ◽  
Surface Growth ◽  
Wide Range ◽  
Air Diffusion

Soot formation and growth in propane/air diffusion flames in a wide range of mole ratio of propane to air from 0.01 to 0.1 have been studied experimentally and theoretically. The concentration of acetylene, soot yield and particle size have been measured and the growth of soot particle has been simulated from surface growth and nucleation processes. The rate coefficient of surface growth has been correlated with the mole ratio of propane to air and the comparisons of particle size between measured and calculated results have been made.

scholarly journals Numerical Study of Hydrogen Addition Fuel on Soot Formation in Axisymmetric Laminar Methane/Air Diffusion Flames

2020 ◽  
Vol 194 ◽  
pp. 04054
Author(s):  
Bencheng Zhu ◽  
Yuhan Zhu ◽  
Jiajia Wu ◽  
Kun Lu ◽  
Yang Wang ◽  
...  
Keyword(s):  
Diffusion Flames ◽  
Soot Formation ◽  
Numerical Study ◽  
Flame Temperature ◽  
Surface Growth ◽  
Chemical Effect ◽  
Oh Radicals ◽  
Phase Reaction ◽  
Hydrogen Addition ◽  
Air Diffusion

This article employs the CoFlame Code to investigate the effects of hydrogen addition to fuel on soot formation characteristics in laminar coflow methane/air diffusion flames at atmospheric pressure. Numerical calculations were carried out using a detailed C1-C2 gas phase reaction mechanism and a soot model consisting of two pyrene molecules colliding into a dimer as soot nucleation, hydrogen abstraction acetylene addition (HACA) and pyrene condensation as surface growth, and soot oxidation by O2, O and OH radicals. Calculations were conducted for five levels of hydrogen addition on volume basis. To quantify the chemical effect of hydrogen, additional calculations are performed for addition of inert pseudo-hydrogen (FH2). The addition of H2 or FH2 does not have a strong influence on flame temperature. The results confirm that hydrogen addition can inhibit soot formation in the methane/air diffusion flame by reducing both the nucleation and surface growth steps of soot formation process. The effect of FH2 addition on soot formation suppression is more remarkable than H2, indicating that the chemical effect of hydrogen added to methane prompts soot formation. The dilution effect of hydrogen addition on soot formation suppression is stronger than its chemical effect on soot formation enhancement the present findings are consistent with those of previous numerical studies.

Soot Particle Evolution and Transport in a Direct Injection Diesel Engine

2015 ◽  
Vol 74 (3) ◽  
Author(s):  
Muhammad Ahmar Zuber ◽  
Wan Mohd Faizal Wan Mahmood ◽  
Zambri Harun ◽  
Zulkhairi Zainol Abidin
Keyword(s):  
Particle Size ◽  
Soot Particle ◽  
Soot Formation ◽  
Formation Rate ◽  
Soot Oxidation ◽  
Surface Growth ◽  
Number Density ◽  
Coagulation Rate ◽  
Particulate Emission ◽  
Soot Particles

Particle-based in-cylinder soot distribution study is becoming more important as the rules and regulations pertaining to particulate emission of diesel-powered vehicles have been increasingly more stringent. This paper focuses on the investigation of soot size evolution and its distribution and transport inside an engine cylinder. The overall process of soot formation includes soot nucleation, surface growth, oxidation, coagulation and agglomeration. The present study considers only soot surface growth, oxidation and coagulation to predict the in-cylinder soot particle size. The soot surface growth model was based on Hiroyasu’s soot formation model while soot oxidation was referred to Nagle & Strickland-Constable’s soot oxidation model. Coagulation rate was defined using Smoluchowski’s equation with constant proposed by Wersborg. From this study, it is demonstrated that soot particles with relatively larger size are gathered in the centre of the cylinder while smaller soot particles are found to be in the region near the wall. Soot number density is considerably high at the start of combustion and reduces sharply afterward while the soot particle size shows the opposite trend. Soot formation rate was found to be dominant at earlier crank angle and is overcome by soot oxidation and coagulation processes that caused lower soot number density but higher soot particle size.  

The influence of nitrogen and hydrogen addition/dilution on soot formation in coflow ethylene/air diffusion flames

Fuel ◽  
2022 ◽  
Vol 309 ◽  
pp. 122244
Author(s):  
Andisheh Khanehzar ◽  
Francisco Cepeda ◽  
Seth B. Dworkin
Keyword(s):  
Diffusion Flames ◽  
Soot Formation ◽  
Hydrogen Addition ◽  
Air Diffusion

scholarly journals Soot particle size measurements in ethylene diffusion flames at elevated pressures

2016 ◽  
Vol 169 ◽  
pp. 85-93 ◽  
Author(s):  
Scott A. Steinmetz ◽  
Tiegang Fang ◽  
William L. Roberts
Keyword(s):  
Particle Size ◽  
Soot Particle ◽  
Diffusion Flames ◽  
Elevated Pressures

scholarly journals A computational study of soot formation and flame structure of coflow laminar methane/air diffusion flames under microgravity and normal gravity

2021 ◽  
Author(s):  
Armin Veshkini ◽  
Seth B. Dworkin
Keyword(s):  
Normal Gravity ◽  
Volume Fraction ◽  
Diffusion Flames ◽  
Soot Formation ◽  
Numerical Study ◽  
Computational Study ◽  
Flame Structure ◽  
Chemical Kinetic ◽  
Surface Growth ◽  
Rate Of Increase

A numerical study is conducted of methane-air coflow diffusion flames at microgravity (μg) and normal gravity (lg), and comparisons are made with experimental data in the literature. The model employed uses a detailed gas phase chemical kinetic mechanism that includes PAH formation and growth, and is coupled to a sectional soot particle dynamics model. The model is able to accurately predict the trends observed experimentally with reduction of gravity without any tuning of the model for different flames. The microgravity sooting flames were found to have lower temperatures and higher volume fraction than their normal gravity counterparts. In the absence of gravity, the flame radii increase due to elimination of buoyance forces and reduction of flow velocity, which is consistent with experimental observations. Soot formation along the wings is seen to be surface growth dominated, while PAH condensation plays a more major role on centerline soot formation. Surface growth and PAH growth increase in microgravity primarily due to increases in the residence time inside the flame. The rate of increase of surface growth is more significant compared to PAH growth, which causes soot distribution to shift from the centerline of the flame to the wings in microgravity. Keywords: laminar diffusion flame,methane-air,microgravity, soot formation, numerical modelling

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