Experimentally Determined Flame Properties near Flammability Limits Under Gravity and Microgravity Conditions

	Experimentally Determined Flame Properties near Flammability Limits Under Gravity and Microgravity Conditions
	Pu YK(浦以康); Hu J(胡俊); Jarosinski J
刊名	Combustion Science and Technology
	2009
通讯作者邮箱	ykpu@imech.ac.cn
卷号	181 期号:12 页码:1431-1442
关键词	Flammability limits, Limit burning velocity, Microgravity
ISSN号	0010-2202
通讯作者	浦以康
合作状况	国际
中文摘要	Flammability limits for flames propagating in a rich propane/air mixture under gravity conditions appeared to be 6.3% C3H8 for downward propagation and 9.2% C3H8 for upward propagation. Different limits might be explained by the action of preferential diffusion of the deficient reactant (Le < 1) on the limit flames, which are in different states of instability. In one of the previous studies, the flammability limits under microgtravity conditions were found to be between the upward and downward limits obtained in a standard flammability tube under normal gravity conditions. It was found in those experiments that there are two limits under microgravity conditions: one indicated by visible flame propagation and another indicated by an increase of pressure without observed flame propagation. These limits were found to be far behind the limit for downward-propagating flame at 1 g (6.3% C3H8) and close to the limit for upward-propagating flame at 1 g (9.2% C3H8). It was decided in the present work to apply a special schlieren system and instant temperature measuring system for drop tower experiments to observe combustion development during propagation of the flame front. A small cubic closed vessel (inner side, 9 cm 9 cm 9 cm) with schlieren quality glass windows were used to study limit flames under gravity and microgravity conditions. Flame development in rich limit mixtures, not visible in previous experiments under microgravity conditions for strait photography, was identified with the use of the schlieren method and instant temperature measuring system. It was found in experiments in a small vessel that there is practically no difference in flammability limits under gravity and microgravity conditions. In this paper, the mechanism of flame propagation under these different conditions is systematically studied and compared and limit burning velocity is estimated.
学科主题	微重力流体力学
类目[WOS]	Thermodynamics ; Energy & Fuels ; Engineering, Multidisciplinary ; Engineering, Chemical
研究领域[WOS]	Thermodynamics ; Energy & Fuels ; Engineering
收录类别	SCI
语种	英语
WOS记录号	WOS:000273386700002
公开日期	2010-03-17
内容类型	期刊论文
源URL	[http://dspace.imech.ac.cn/handle/311007/33065]
专题	力学研究所_国家微重力实验室
推荐引用方式 GB/T 7714	Pu YK,Hu J,Jarosinski J. Experimentally Determined Flame Properties near Flammability Limits Under Gravity and Microgravity Conditions[J]. Combustion Science and Technology,2009,181(12):1431-1442.
APA	浦以康,胡俊,&Jarosinski J.(2009).Experimentally Determined Flame Properties near Flammability Limits Under Gravity and Microgravity Conditions.Combustion Science and Technology,181(12),1431-1442.
MLA	浦以康,et al."Experimentally Determined Flame Properties near Flammability Limits Under Gravity and Microgravity Conditions".Combustion Science and Technology 181.12(2009):1431-1442.