Numerical study of laminar flame speed of fuel-stratified hydrogen/air   flames

doi:10.1016/j.combustflame.2015.10.014

CORC > 北京大学 > 工学院

	Numerical study of laminar flame speed of fuel-stratified hydrogen/air flames
	Shi, Xian ; Chen, Jyh-Yuan ; Chen, Zheng
刊名	COMBUSTION AND FLAME
	2016
关键词	Hydrogen/air stratified flame Laminar flame speed Fuel consumption speed Flame front propagation speed Differential diffusion PROPAGATING SPHERICAL FLAMES AIR MIXTURES CHARGE STRATIFICATION FLAMMABILITY LIMITS BURNING VELOCITIES PREMIXED FLAMES TRIPLE FLAMES COMBUSTION ENGINE COMPRESSION
DOI	10.1016/j.combustflame.2015.10.014
英文摘要	Numerical studies on hydrogen/air stratified flames in 1-D planar coordinate are performed using a time-accurate and space-adaptive numerical solver A-SURF. A step change in equivalence ratio is initialized as fuel stratification. Flame characterizations including fuel consumption speed and flame front propagation speed are compared between stratified flames and corresponding homogeneous flames. Two transport models, with equal diffusivity and mixture-average diffusivity assumptions respectively, are considered. With equal diffusivity assumption and stratification thickness larger than flame thickness, local fuel consumption speeds of stratified and homogeneous flames are identical, indicating that neither thermal effect nor chemical effect is present in stratified flames. When stratification thickness is reduced to the order of flame thickness, the difference between local fuel consumption speeds of stratified and homogeneous flames is caused by chemical effect due to different level of H radical in burnt gas. The same mechanism also leads to the difference between local fuel consumption speeds with mixture-average diffusivity assumption. In addition, preferential diffusion of H radical further increases the difference. The difference between flame front propagation speeds of stratified and homogeneous flames is mainly caused by additional heat release in the burnt gas with equal diffusivity assumption, while the difference with mixture-average diffusivity assumption is mainly caused by local chemical effect. Hydrodynamic effect due to fluid continuity on flame front propagation speeds is observed in both transport models. Additionally, with increasing stratification thickness, both local chemical and hydrodynamic effect are reduced. No significant lean flammability extension of hydrogen/air mixture is introduced by fuel stratification. (C) 2015 The Combustion Institute. Published by Elsevier Inc. All rights reserved.; National Science Foundation; U.S. Department of Energy [CBET-1258653]; National Natural Science Foundation of China [51322602]; SCI(E); EI; ARTICLE; xshi@berkeley.edu; 394-405; 163
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/437897]
专题	工学院
推荐引用方式 GB/T 7714	Shi, Xian,Chen, Jyh-Yuan,Chen, Zheng. Numerical study of laminar flame speed of fuel-stratified hydrogen/air flames[J]. COMBUSTION AND FLAME,2016.
APA	Shi, Xian,Chen, Jyh-Yuan,&Chen, Zheng.(2016).Numerical study of laminar flame speed of fuel-stratified hydrogen/air flames.COMBUSTION AND FLAME.
MLA	Shi, Xian,et al."Numerical study of laminar flame speed of fuel-stratified hydrogen/air flames".COMBUSTION AND FLAME (2016).