Effect of channel surface wettability and temperature gradients on the boiling flow pattern in a single microchannel
文献类型：期刊论文
| 作者 | Zhang, Wei1; Liu, Guohua1; Xu, Jinliang1; Yang, Yongping2 |
| 刊名 | journal of micromechanics and microengineering
 |
| 出版日期 | 2009-05-01 |
| 卷号 | 19期号:5页码:055012 |
| 关键词 | HEAT SINKS INSTABILITIES CONDENSATION |
| 通讯作者 | xujl@ms.giec.ac.cn |
| 中文摘要 | the objective of this paper is to investigate the effects of channel surface wettability and temperature gradients on the boiling flow pattern in a single microchannel. the test section consists of a bottom silicon substrate bonded with a top glass cover. three consecutive parts of an inlet fluid plenum, a central microchannel and an outlet fluid plenum were etched in the silicon substrate. the central microchannel had a width of 800 mu m and a depth of 30 mu m. acetone liquid was used as the working fluid. high outlet vapor qualities were dealt with here. the flow pattern consists of a fluid triangle (shrinkage of the liquid films) and a connected long liquid rivulet, which is generated in the central microchannel in the timescale of milliseconds. the peculiar flow pattern is formed due to the following reasons: (1) the liquid rivulet tends to have a large contact area with the top hydrophilic channel surface of the glass cover, but a smaller contact area with the bottom silicon hydrophobic surface. (2) the temperature gradient in the chip width direction at the top channel surface of the glass cover not only causes the shrinkage of the liquid films in the central microchannel upstream, but also attracts the liquid rivulet populated near the microchannel centerline. (3) the zigzag pattern is formed due to the competition between the evaporation momentum forces at the vapor-liquid interfaces and the force due to the marangoni effect. the former causes the rivulet to deviate from the channel centerline and the latter draws the rivulet toward the channel centerline. (4) the temperature gradient along the flow direction in the central microchannel downstream causes the breakup of the rivulet to form isolated droplets there. (5) liquid stripes inside the upstream fluid triangle were caused by the small capillary number of the liquid film, at which the large surface tension force relative to the viscous force tends to populate the liquid film locally on the top glass cover surface. |
| 英文摘要 | the objective of this paper is to investigate the effects of channel surface wettability and temperature gradients on the boiling flow pattern in a single microchannel. the test section consists of a bottom silicon substrate bonded with a top glass cover. three consecutive parts of an inlet fluid plenum, a central microchannel and an outlet fluid plenum were etched in the silicon substrate. the central microchannel had a width of 800 mu m and a depth of 30 mu m. acetone liquid was used as the working fluid. high outlet vapor qualities were dealt with here. the flow pattern consists of a fluid triangle (shrinkage of the liquid films) and a connected long liquid rivulet, which is generated in the central microchannel in the timescale of milliseconds. the peculiar flow pattern is formed due to the following reasons: (1) the liquid rivulet tends to have a large contact area with the top hydrophilic channel surface of the glass cover, but a smaller contact area with the bottom silicon hydrophobic surface. (2) the temperature gradient in the chip width direction at the top channel surface of the glass cover not only causes the shrinkage of the liquid films in the central microchannel upstream, but also attracts the liquid rivulet populated near the microchannel centerline. (3) the zigzag pattern is formed due to the competition between the evaporation momentum forces at the vapor-liquid interfaces and the force due to the marangoni effect. the former causes the rivulet to deviate from the channel centerline and the latter draws the rivulet toward the channel centerline. (4) the temperature gradient along the flow direction in the central microchannel downstream causes the breakup of the rivulet to form isolated droplets there. (5) liquid stripes inside the upstream fluid triangle were caused by the small capillary number of the liquid film, at which the large surface tension force relative to the viscous force tends to populate the liquid film locally on the top glass cover surface. |
| WOS标题词 | science & technology ; technology |
| 类目[WOS] | engineering, electrical & electronic ; nanoscience & nanotechnology ; instruments & instrumentation ; materials science, multidisciplinary ; mechanics |
| 研究领域[WOS] | engineering ; science & technology - other topics ; instruments & instrumentation ; materials science ; mechanics |
| 关键词[WOS] | heat sinks ; instabilities ; condensation |
| 收录类别 | SCI |
| 资助信息 | national natural science foundation of china [50825603]; natural science foundation of china [50776089] |
| 语种 | 英语 |
| WOS记录号 | WOS:000265580900022 |
| 公开日期 | 2010-09-15 |
| 源URL | [http://ir.giec.ac.cn/handle/344007/3288]  |
| 专题 | 中国科学院广州能源研究所 |
| 作者单位 | 1.Chinese Acad Sci, Guangzhou Inst Energy Convers, Micro Energy Syst Lab, Guangzhou 510640, Peoples R China 2.N China Elect Power Univ, Beijing Key Lab Energy Safety & Clean Utilizat, Beijing 102206, Peoples R China |
| 推荐引用方式 GB/T 7714 | Zhang, Wei,Liu, Guohua,Xu, Jinliang,et al. Effect of channel surface wettability and temperature gradients on the boiling flow pattern in a single microchannel[J]. journal of micromechanics and microengineering,2009,19(5):055012. |
| APA | Zhang, Wei,Liu, Guohua,Xu, Jinliang,&Yang, Yongping.(2009).Effect of channel surface wettability and temperature gradients on the boiling flow pattern in a single microchannel.journal of micromechanics and microengineering,19(5),055012. |
| MLA | Zhang, Wei,et al."Effect of channel surface wettability and temperature gradients on the boiling flow pattern in a single microchannel".journal of micromechanics and microengineering 19.5(2009):055012. |
入库方式： OAI收割
来源：广州能源研究所
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