Knowledge Management System Of Guangzhou Institute of Energy Conversion, CAS
| 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 | |
| 2007-03-01 | |
| Source Publication | INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
 |
| ISSN | 0017-9310 |
| Volume | 50Issue:5-6Pages:857-871 |
| Corresponding Author | xujl@ms.giec.ac.cn |
| Abstract | 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. |
| Subtype | Article |
| Other Abstract | 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. |
| Keyword | Flow Patterns Microchannel Reactor Hydrogen Peroxide Bubble Slug Length Liquid Slug Microthruster |
| WOS Headings | Science & Technology ; Physical Sciences ; Technology |
| DOI | 10.1016/j.ijheatmasstransfer.2006.08.017 |
| WOS Subject Extended | Thermodynamics ; Engineering ; Mechanics |
| URL | 查看原文 |
| WOS Keyword | 2-PHASE FLOW ; HEAT-TRANSFER ; LIQUID FLOW ; MICROTHRUSTER ; CHANNELS |
| Indexed By | SCI |
| Language | 英语 |
| WOS Subject | Thermodynamics ; Engineering, Mechanical ; Mechanics |
| WOS ID | WOS:000244575000007 |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.giec.ac.cn/handle/344007/3478 |
| Collection | 中国科学院广州能源研究所 |
| Affiliation | Chinese Acad Sci, Micro Energy Syst Lab, Guangzhou Inst Energy Convers, Guangzhou 510640, Peoples R China |
| Recommended Citation 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. |
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