题名 | Rarefied flow separation in microchannel with bends |
作者 | |
通讯作者 | Li, Jun; Zhang, Yonghao |
发表日期 | 2020-10-25
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DOI | |
发表期刊 | |
ISSN | 0022-1120
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EISSN | 1469-7645
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卷号 | 901 |
摘要 | Based on an accurate numerical solution of the kinetic equation using well-resolved spatial and velocity grids, the separation of rarefied gas flow in a microchannel with double rectangular bends is investigated over a wide range of Knudsen and Reynolds numbers. Rarefaction effects are found to play different roles in flow separation (vortex formation) at the concave and convex corners. Flow separations near the concave and convex corners are only observed for a Knudsen number up to and , respectively. With further increase of the Knudsen number, flow separation disappears. Due to the velocity slip at the solid walls, the concave (convex) vortex is suppressed (enhanced), which leads to the late (early) onset of separation of rarefied gas flows with respect to the Reynolds number. The critical Reynolds numbers for the emergence of concave and convex vortices are found to be as low as 0.32 x 10(-3) and 30.8, respectively. The slip velocity near the concave (convex) corner is found to increase (decrease) when the Knudsen number increases. An adverse pressure gradient appears near the concave corner for all the examined Knudsen numbers, while for the convex corner it only occurs when the Knudsen number is less than . Due to the secondary flow and adverse pressure gradient near the rectangular bends, the mass flow rate ratio between the bent and straight channels of the same length is a non-monotonic function of the Knudsen number. Our results clarify the diversified and often contradictory observations reported in the literature about flow rate enhancement and vortex formation in bent microchannels. |
关键词 | |
相关链接 | [来源记录] |
收录类别 | |
语种 | 英语
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学校署名 | 其他
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资助项目 | National Key Basic Research and Development Program[2014CB744100]
; National Natural Science Foundation of China[11325212]
; UK Engineering and Physical Sciences Research Council[EP/R041938/1]
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WOS研究方向 | Mechanics
; Physics
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WOS类目 | Mechanics
; Physics, Fluids & Plasmas
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WOS记录号 | WOS:000565254500001
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出版者 | |
EI入藏号 | 20203909248392
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EI主题词 | Flow of gases
; Integral equations
; Vortex flow
; Gases
; Microchannels
; Reynolds number
; Pressure gradient
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EI分类号 | Fluid Flow:631
; Fluid Flow, General:631.1
; Gas Dynamics:631.1.2
; Calculus:921.2
; Pressure Measurements:944.4
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ESI学科分类 | ENGINEERING
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来源库 | Web of Science
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引用统计 |
被引频次[WOS]:21
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成果类型 | 期刊论文 |
条目标识符 | http://sustech.caswiz.com/handle/2SGJ60CL/186571 |
专题 | 工学院_力学与航空航天工程系 |
作者单位 | 1.Univ Strathclyde, Dept Mech & Aerosp Engn, James Weir Fluids Lab, Glasgow G1 1XJ, Lanark, Scotland 2.King Fahd Univ Petr & Minerals, Coll Petr Engn & Geosci, Ctr Integrat Petr Res, Dhahran 31261, Saudi Arabia 3.Southern Univ Sci & Technol, Dept Mech & Aerosp Engn, Shenzhen 518055, Guangdong, Peoples R China 4.Univ Edinburgh, Sch Engn, Edinburgh EH9 3FB, Midlothian, Scotland 5.China Aerodynam Res & Dev Ctr, Hyperveloc Aerodynam Inst, Mianyang 621000, Sichuan, Peoples R China |
推荐引用方式 GB/T 7714 |
Ho, Minh Tuan,Li, Jun,Su, Wei,et al. Rarefied flow separation in microchannel with bends[J]. JOURNAL OF FLUID MECHANICS,2020,901.
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APA |
Ho, Minh Tuan.,Li, Jun.,Su, Wei.,Wu, Lei.,Borg, Matthew K..,...&Zhang, Yonghao.(2020).Rarefied flow separation in microchannel with bends.JOURNAL OF FLUID MECHANICS,901.
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MLA |
Ho, Minh Tuan,et al."Rarefied flow separation in microchannel with bends".JOURNAL OF FLUID MECHANICS 901(2020).
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条目包含的文件 | 条目无相关文件。 |
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