Transient flow patterns and bubble slug lengths in parallel microchannels with oxygen gas bubbles produced by catalytic chemical reactions

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	Transient flow patterns and bubble slug lengths in parallel microchannels with oxygen gas bubbles produced by catalytic chemical reactions
	Xu, Jinliang; Feng, Yi; Cen, Jiwen
刊名	international journal of heat and mass transfer
	2007-03-01
卷号	50 期号:5-6 页码:857-871
关键词	flow patterns microchannel reactor hydrogen peroxide bubble slug length liquid slug microthruster
ISSN号	0017-9310
通讯作者	xujl@ms.giec.ac.cn
中文摘要	transient flow patterns and bubble slug lengths were investigated with oxygen gas (o-2) bubbles produced by catalytic chemical reactions using a high speed camera bonded with a microscope. the microreactor consists of an inlet liquid plenum, nine parallel rectangular microchannels followed by a micronozzle, using the mems fabrication technique. the etched surface was deposited by the thin platinum film, which is acted as the catalyst. experiments were performed with the inlet mass concentration of the hydrogen peroxide from 50% to 90% and the pressure drop across the silicon chip from 2.5 to 20.0 kpa. the silicon chip is directly exposed in the environment thus the heat released via the catalytic chemical reactions is dissipated into the environment and the experiment was performed at the room temperature level. it is found that the two-phase flow with the catalytic chemical reactions display the cyclic behavior. a full cycle consists of a short fresh liquid refilling stage, a liquid decomposition stage followed by the bubble slug flow stage. at the beginning of the bubble slug flow stage, the liquid slug number reaches maximum, while at the end of the bubble slug flow stage the liquid slugs are quickly flushed out of the microchannels. two or three large bubbles are observed in the inlet liquid plenum, affecting the two-phase distributions in microchannels. the bubble slug lengths, cycle periods as well as the mass flow rates are analyzed with different mass concentrations of hydrogen peroxide and pressure drops. the bubble slug length is helpful for the selection of the future microreactor length ensuring the complete hydrogen peroxide decomposition. future studies on the temperature effect on the transient two-phase flow with chemical reactions are recommended.
英文摘要	transient flow patterns and bubble slug lengths were investigated with oxygen gas (o-2) bubbles produced by catalytic chemical reactions using a high speed camera bonded with a microscope. the microreactor consists of an inlet liquid plenum, nine parallel rectangular microchannels followed by a micronozzle, using the mems fabrication technique. the etched surface was deposited by the thin platinum film, which is acted as the catalyst. experiments were performed with the inlet mass concentration of the hydrogen peroxide from 50% to 90% and the pressure drop across the silicon chip from 2.5 to 20.0 kpa. the silicon chip is directly exposed in the environment thus the heat released via the catalytic chemical reactions is dissipated into the environment and the experiment was performed at the room temperature level. it is found that the two-phase flow with the catalytic chemical reactions display the cyclic behavior. a full cycle consists of a short fresh liquid refilling stage, a liquid decomposition stage followed by the bubble slug flow stage. at the beginning of the bubble slug flow stage, the liquid slug number reaches maximum, while at the end of the bubble slug flow stage the liquid slugs are quickly flushed out of the microchannels. two or three large bubbles are observed in the inlet liquid plenum, affecting the two-phase distributions in microchannels. the bubble slug lengths, cycle periods as well as the mass flow rates are analyzed with different mass concentrations of hydrogen peroxide and pressure drops. the bubble slug length is helpful for the selection of the future microreactor length ensuring the complete hydrogen peroxide decomposition. future studies on the temperature effect on the transient two-phase flow with chemical reactions are recommended. (c) 2006 elsevier ltd. all rights reserved.
WOS标题词	science & technology ; physical sciences ; technology
类目[WOS]	thermodynamics ; engineering, mechanical ; mechanics
研究领域[WOS]	thermodynamics ; engineering ; mechanics
关键词[WOS]	2-phase flow ; heat-transfer ; liquid flow ; microthruster ; channels
收录类别	SCI
原文出处	http://www.sciencedirect.com/science/journal/00179310
语种	英语
WOS记录号	WOS:000244575000007
公开日期	2010-09-27
内容类型	期刊论文
源URL	[http://ir.giec.ac.cn/handle/344007/3478]
专题	中国科学院广州能源研究所
作者单位	Chinese Acad Sci, Micro Energy Syst Lab, Guangzhou Inst Energy Convers, Guangzhou 510640, Peoples R China
推荐引用方式 GB/T 7714	Xu, Jinliang,Feng, Yi,Cen, Jiwen. Transient flow patterns and bubble slug lengths in parallel microchannels with oxygen gas bubbles produced by catalytic chemical reactions[J]. international journal of heat and mass transfer,2007,50(5-6):857-871.
APA	Xu, Jinliang,Feng, Yi,&Cen, Jiwen.(2007).Transient flow patterns and bubble slug lengths in parallel microchannels with oxygen gas bubbles produced by catalytic chemical reactions.international journal of heat and mass transfer,50(5-6),857-871.
MLA	Xu, Jinliang,et al."Transient flow patterns and bubble slug lengths in parallel microchannels with oxygen gas bubbles produced by catalytic chemical reactions".international journal of heat and mass transfer 50.5-6(2007):857-871.