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Numerical study on flame structure and NO formation in CH 4 –O 2 –N 2 counterflow diffusion flame diluted with H 2 O
Author(s) -
Hwang DongJin,
Choi JongWook,
Park Jeong,
Keel SangIn,
Ch ChangBo,
Noh DongSoon
Publication year - 2004
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.1028
Subject(s) - diffusion flame , chemistry , flame structure , chemical reaction , diffusion , branching (polymer chemistry) , adiabatic flame temperature , chain reaction , thermodynamics , thermal , reaction rate , chemical species , radical , combustion , chemical engineering , organic chemistry , photochemistry , combustor , physics , engineering , catalysis
Numerical study on flame structure and NO emission behaviour has been conducted to grasp chemical effects of added H 2 O on either fuel‐ or oxidizer‐side in CH 4 –O 2 –N 2 counterflow diffusion flames. An artificial species, which has the same thermodynamic, transport, and radiation properties of added H 2 O, is introduced to feasibly isolate the chemical effects. Special concern is focused on the important role of remarkably produced OH radicals due to chemical effects of added H 2 O on flame structure and NO emission. The reason why the difference of behaviours between the principal chain branching reaction rate and flame temperature appear is attributed to the drastic change of reaction step (R120) from the production to the consumption of OH. It is also, however, seen that the most important contribution of produced OH due to chemical effects of added H 2 O is through reaction step (R127). The importantly contributing reaction steps to NO production are also examined. The production rates of thermal NO and prompt NO are suppressed by chemical effects of added H 2 O. The contribution of the reaction steps related to HNO intermediate species to the production of prompt NO is also stressed. Copyright © 2004 John Wiley & Sons, Ltd.