随机粗糙微通道内部流动与传质特性

摘要/Abstract

摘要： 为了研究微通道壁面随机粗糙度对流体流动和传质特性的影响，采用随机排布准则构建具有典型粗糙元类型的随机粗糙微通道壁面，利用有限元方法分析壁面随机粗糙度对流速、压降、流动阻力和传质性能的影响，并给出粗糙微通道内部Poiseuille数和分子传质扩散的近似变化规律。结果表明，流体在粗糙微通道近壁面区域和主流区的流速差异较大，近壁面区域流动分离现象明显；与光滑微通道相比，粗糙微通道内部各位置的压降和Poiseuille数沿着流动方向呈近似线性增大趋势；微通道壁面粗糙度的存在可以强化流体分子的传质扩散速率，但受粗糙度类型和相对粗糙度的影响较大。

关键词: 微通道, 壁面随机粗糙度, Poiseuille数, 传质

Abstract: Abstract:In order to study the effects of random roughness on the flow and mass transfer characteristics of the microchannel walls，the random roughness of the microchannel walls with typical roughness was established using the random arrangement criterion.The effects of random roughness on velocity，pressure drop，flow resistance and mass transfer characteristics were analyzed by finite element method，and the approximate variation law of Poiseuille number and molecular diffusion in rough microchannels were given.Results show that the flow velocity of the fluid in the near-wall areas and the mainstream regions of the coarse microchannels is quite different，and the flow separation in the near-wall areas is obvious.Compared with the smooth microchannels，the pressure drop and the Poiseuille number in each positions of the microchannels increase linearly along the flow direction.The existence of the microchannel wall roughness accelerates the diffusion rate of fluid molecules mass transfer，butit is greatly affected by roughness type and relative roughness height.

Key words: microchannel；random surface roughness of wall surface； Poiseuille number, mass transfer

中图分类号:

O351
TQ027

鲁聪达;薛浩;吴化平;文东辉. 随机粗糙微通道内部流动与传质特性[J]. 中国机械工程.

LU Congda;XUE Hao;WU Huaping;WEN Donghui. Flow and Mass Transfer Characteristics in Random Roughness Surface Microchannels[J]. China Mechanical Engineering.

参考文献

[1]AMINI H，LEE W，CARLO D D.Inertial Microfluidic Physics[J].Lab Chip，2014,14（15)：2739-2761.
[2]SAJEESH P，SEN A K.Particle Separation and Sorting in Microfluidic Devices：a Review[J].Microfluidics and Nanofluidics，2013,17（1)：1-52.
[3]BRULL S，CHARRIER P，MIEUSSENS L.Nanoscale Roughness Effect on Maxwell-like Boundary Conditions for the Boltzmann Equation[J].Physics of Fluids，2016,28（8)：082004.
[4]LIU P，LAMARCHE C Q，KELLOGG K M，et al.Cohesive Grains：Bridging Microlevel Measurements to Macrolevel Flow Behavior via Surface Roughness[J].AIChE Journal，2016,62（10)：3529-3537.
[5]RAWOOL A S，MITRA S K，KANDLIKAR S G.Numerical Simulation of Flow Through Microchannels with Designed Roughness[J].Microfluidics and Nanofluidics，2005,2（3)：215-221.
[6]CHEN Y，ZHANG C，FU P，et al.Characterization of Surface Roughness Effects on Laminar Flow in Microchannels by Using Fractal Cantor Structures[J].Journal of Heat Transfer，2012,134（5)：051011.
[7]NATRAJAN V K，CHRISTENSEN K T.The Impact of Surface Roughness on Flow through a Rectangular Microchannel from the Laminar to Turbulent Regimes[J].Microfluidics and Nanofluidics，2009,9（1)：95-121.
[8]YUAN X，TAO Z，LI H，et al.Experimental Investigation of Surface Roughness Effects on Flow Behavior and Heat Transfer Characteristics for Circular Microchannels[J].Chinese Journal of Aeronautics，2016,29（6)：1575-1581.
[9]KHARATI-KOOPAEE M，ZARE M.Effect of Aligned and Offset Roughness Patterns on the Fluid Flow and Heat Transfer within Microchannels Consist of Sinusoidal Structured Roughness[J].International Journal of Thermal Sciences，2015,90：9-23.
[10]JAIN V K，KALIA S，SIDPARA A M.Some Aspects of Fabrication of Micro Devices by Electrochemical Micromachining （ECMM) and Its Finishing by Magnetorheological Fluid[J].The International Journal of Advanced Manufacturing Technology，2011,59（9/12)：987-996.
[11]PENDHARKAR G，DESHMUKH R，PATRIKAR R.Investigation of Surface Roughness Effects on Fluid Flow in Passive Micromixer[J].Microsystem Technologies，2013,20（12)：2261-2269.
[12]MORINI GL，YANG Y，CHALABI H，et al.A Critical Review of the Measurement Techniques for the Analysis of Gas Microflows through Microchannels[J].Experimental Thermal and Fluid Science，2011,35（6)：849-865.
[13]BOCQUET L，CHARLAIX E.Nanofluidics，from Bulk to Interfaces[J].Chemical Society Reviews，2010,39（3)：1073-1095.
[14]谭德坤，刘莹.壁面粗糙度效应对微流体流动特性的影响[J].中国机械工程，2015，26（9):1210-1214.
TAN Dekun，LIU Ying.Effects of Wall Roughness on Pressure-driven Liquid Flow in Microchannels[J].China Mechanical Engineering，2015，26（9):1210-1214.
[15]DORARI E，SAFFAR-AVVAL M，MANSOORI Z.Numerical Simulation of Gas Flow and Heat Transfer in a Rough Microchannel Using the Lattice Boltzmann Method[J].Physical Review E Statistical Nonlinear & Soft Matter Physics，2015,92（6)：063034.
[16]GUO L，XU H，GONG L.Influence of Wall Roughness Models on Fluid Flow and Heat Transfer in-Microchannels[J].Applied Thermal Engineering，2015,84：399-408.
[17]KANG S，SUH Y K.Numerical Analysis on Electroosmotic Flows in a Microchannel with Rectangle-waved Surface Roughness Using the Poisson-Nernst-Planck Model[J].Microfluidics and Nanofluidics，2008,6（4)：461-477.
[18]高新学，云和明.平板微通道流动入口段粗糙度效应的数值模拟[J].中国机械工程，2011,22（3):326-330.
GAO Xinxue，YUN Heming.Numerical Simulation of Roughness Effects on Flow Entrance in Flat Micro-channels[J].China Mechanical Engineering，2011,22（3):326-330.
[19]ALAM A，KIM K Y.Analysis of Mixing in a Curved Microchannel with Rectangular Grooves[J].Chemical Engineering Journal，2012,181/182（2)：708-716.
[20]ZHANG J，DIAO Y H，ZHAO Y H，et al.An Experimental Study of the Characteristics of Fluid Flow and Heat Transfer in the Multiport Microchannel Flat Tube[J].Applied Thermal Engineering，2014,65（1/2)：209-218.
[21]LIU Z.Effects of Geometry on Liquid Flow and Heat Transfer in Microchannels[J].Journal of Mechanical Engineering，2012,48（16)：139