克努森数在微尺度相似流动特性研究中的作用

许艳芝; 朱惠人; 郑杰

克努森数在微尺度相似流动特性研究中的作用

西北工业大学动力与能源学院, 西安 710072

基金项目: 国家重点基础研究发展计划(2013CB035702)

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出版历程
- 收稿日期: 2012-08-01
- 刊出日期: 2013-08-28

Effect of Knudsen number on microscale similar flow characteristics

School of Power and Energy, Northwestern Polytechnical University, Xi'an 710072, China

摘要

摘要: 为了研究克努森数对微尺度相似流动的影响,选取孔径分别为3,1,0.5,0.3mm的相似小孔模型并视流体为连续介质,在相同的雷诺数下对各尺度小孔流体克努森数不同和相同的情况进行数值模拟,计算小孔的质量流量系数并分析其内部流场特征.结果表明:在相同的雷诺数下,原件与放大件的内部流场在克努森数相同时表现出更好的相似性,小孔质量流量系数也表现出更好的吻合性,因此在采用相似放大模型研究微小尺度结构的流动特性时,为了得到更为准确的结果,必须保证相似放大件和微尺度原件克努森数相同.
- 相似流动 /
- 克努森数 /
- 连续介质 /
- 质量流量系数 /
- 涡旋 /
- 边界
Abstract: Four similar hole models with the aperture of 3,1,0.5 and 0.3mm were selected,with the fluid regarded as continuous medium to investigate the effect of Knudsen number on the characteristics of microscale similar flow.The mass flow rate coefficient was calculated by numerical simulation when the Knudsen number of fluid with each scale pore was variable and constant at the same Reynolds number,and then the internal flow field was analyzed.The results show that when the Knudsen numbers of the four hole models are equal,the internal flow fields and the mass flow rate coefficients of different scale pores show a better similarity at the same Reynolds number,so it is required to ensure the same Knudsen number to get more accurate results in investigating the flow characteristics of microscale structure by amplificatory models.
- similar flow /
- Knudsen number /
- continuum medium /
- mass flow rate coefficient /
- vortex /
- boundary

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参考文献(15)

[1]	陶然,权晓波,徐建中.微尺度流动研究中的几个问题[J].工程热物理学报,2001,22(5):575-577. TAO Ran,QUAN Xiaobo,XU Jianzhong.Several quetions in research of micro scale flow[J].Journal of Engineering Theromophysics,2001,22(5):575-577.(in Chinese)
[2]	李战华,崔海航.微尺度流动特性[J].机械强度,2001,23(4):476-480. LI Zhanhua,CUI Haihang.Characters of micro scale flow[J].Journal of Mechanical Strength,2001,23(4):476-480.(in Chinese)
[3]	刘静.微米/纳米尺度热科学与工程学中的若干重要问题和发展[J].物理,2001,30(7):398-406. LIU Jing.Some important issues of micro/nano-scale thermal science and engineering[J].Physic,2001,30(7):398-406.(in Chinese)
[4]	Eringen A C.Simple microfluids[J].International Journal of Engineering Science,1964,2(2):205-217.
[5]	Mala G M,Li D Q.Flow characteristic of water in microtubes[J].International Journal of Heat and Fluid Flow,1999,20(2):142-148.
[6]	Weilin Q,Mala G M,Dongqing L.Pressure-driven water flows in trapezoidal silicon microchannels[J].International Journal of Heat and Mass Transfer,2000,43(3):353-364.
[7]	Chen Y T,Kang S W,Tuh W C,et al.Experimental investigation of fluid flow and heat transfer in microchannels[J].Tamkang Journal of Science and Engineering,2004,7(1):11-16.
[8]	Gad-ei-Hak M.Fluid mechanics of microdevices:the freeman scholar lecture[J].Journal of Fluids Engineering,1999,121(2):5-33.
[9]	LI Junming,WANG Buxuan,PENG Xiaofeng.A model for predicting laminar gas flow through micropassages[J].Thermal Science,1997,6(4):279-285.
[10]	LI Junming,WANG Buxuan,PENG Xiaofeng.Wall adjacent layer'analysis for develop-flow laminar heat of gases in microchannels[J].International Journal of Heat and Mass Transfer,2000,43(5):837-847.
[11]	AN Gang,LI Junming,WANG Buxuan.Laminar heat transfer of gas in a parallel-plate microchannel with one wall temperature constant and the other adiabatic[J].Heat Transfer-Asian Research,2003,32(1):58-64.
[12]	Beskok A.Validation of a new velocity-slip model for separated gas micro flows[J].Numerical Heat Transfer,2001,40(6):451-471.
[13]	Pfahler J,Harley J,Bau H,et al.Gas and liquid flow in small channels[J].ASME Dynamic Systems and Control Division,1991,32:49-60.
[14]	邬小波,过增元.微细光滑管内气体的流动与传热特性研究[J].工程热物理学报,1997,18(3):326-330. WU Xiaobo,GUO Zengyuan.Investigation of gas flow and heat transfer in smooth microtubes[J].Journal of Engineering Thermophysics,1997,18(3):326-330.(in Chinese)
[15]	张效伟,朱惠人,张霞,等.小尺度孔的流量系数试验[J].航空动力学报,2010,25(11):2479-2485. ZHANG Xiaowei,ZHU Huiren,ZHANG Xia,et al.Experiment of discharge coefficients for small scale cylindrical holes[J].Journal of Aerospace Power,2010,25 (11):2479-2485.(in Chinese)