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標題: 週期性電場與壓力梯度驅動之微流道混合特性的數值分析-曲率之影響
Numerical Analysis of Mixing on the Microflow driven by Periodic Electric and Pressure Field - Effect of curvature.
作者: 彭育傑
Peng, Yu-Chieh
關鍵字: Electroosmosis;電滲流;Micro-Mixing;Electric field;Pressure gradient;微混合;電場;壓力梯度
出版社: 機械工程學系所
引用: [1] Griffiths, K. and Nilson H. ,“Band Spreading in Two-Dimensional Microchannel Turns for Electrokinetic Species Transport”, Analytical Chemistry, 2000, Vol. 72, No.21,pp. 5473-5482 . [2] Dutta, P., Beskok, A. ,”Analytical Solution of Combined Eletroosmotic/Pressure Driven Flows in Two-Dimensional Straight Channels: Finite Debye Layer Effects”, Analytical Chemistry, 2001, Vol.73, No.9, pp.1979-1986. [3] Dutta, P., Beskok, A. and Warburton, T. C., “Numercial Simulation of Mixed Electroosmotic/Pressure Driven Microflows”, Numercial Heat Transfer, Part A, 2002, Vol. 41, pp. 131-148. [4] Ren, L. Escobedo-Canseco, C. and Li, D. , “A New Method of the Average Electro-osmotic Velocity in Microchannels,” Jounal of Colloid and Interface Science , 2002 , Vol. 250 , pp. 238-242 . [5] Osuga, T.,“Comparision of Growth of Laminar Flows in Capillary: Poiseuille Flow, Electroosmotic Flow and Electroosmotic Circulation”, Japan Journal Applied Physics, 1999, Vol. 38, pp. 6564-6567 . [6] Nguyen, N-T., and Wu, Z., “Micromixers-a Review,” Journal of Micromechanical and Microengineering , 2005 , Vol. 15, No.2 , R1-R16 . [7] Myake, R., Lammerink, T. S. J., Elwenspoek, M.,and Fluitman, J. H. J.,“Micro Mixer with Fast Diffusion”, Proceeding of the IEEE Micro Electro Mechanical Workshop, Fort Lauderale, FL, 1993, pp. 248-253 . [8] Deshmukh, M., Brasseur, G. and Daldal, F.,“Novel Rhodobacter Capsulatus Genes Required for the Biogenesis of Various C-type Cytochromes”, Molecular Microbiology, 2000, Vol. 35, pp. 123–138. [9] Yang, R.-J., Fu, L.-M. and Lin, Y.-C., “Electroosmotic Entry Flow in Microchannels”, J. Colloid Interface Science, Vol. 244, 2001, pp. 173-179. [10] Deval, J., Tabeling, P. and Ho, C. M., “A Dielectrophoretic Chaotic Mixer”, Proceeding of IEEE International Conference, MEMS, 2002, pp. 36-39. [11] Branebjerg, J., Gravesen, P., Krog, J. P., and Nielsen, C. R.,“Fast Mixing by Lamination”, Proceedings of the 9th Annual Workshop on Micro Electro Mechanical Systems, San Diego, CA, 1996, pp. 441-446 . [12] Liu, R. H., Stremler, M. A., Sharp, K. V., Olsen, M. G., Santiago, J. G., Adrian, R. J., Aref, H. and Beebe, D. J.,“Passive Mixing in a Three-Dimensional Serpentine Microchannel”, Journal of Microelectromechanical System, 2000, Vol 9, pp. 190–197. [13] Friedhelm, S. and Steffen, H., ”Simulation of Helical Flow in Microchannels,” AIChE Journal, 2004, April,Vol. 50, No. 4, pp. 771-778 . [14] Jiang, F., Drese, K. S., Heardt, S., Kupper, M. and Schonfeld, F.,“Helical Flows and Chaotic Mixing in Curved Micro Channels,” AIChE Journal, 2004, September, Vol. 50, No. 9, pp. 2297-2305 . [15] Tian, F., Li, B., and Y. Kwok, D.,“Tradeoff between Mixing and Transport for Electroosmotic Flow in Heterogeneous Microchannel with Nnuniform Surface Potentials,”Langmuir 2005 , Vol 21, pp. 1126-1131. [16] 馬茀綺,“新型微電動液壓幫浦驅動之微混合器”, 國立成功大學, 航空太空工程學系碩士論文, 2002. [17] 吳詩儀,“微型三維混合系統於生醫晶片之研發與應用”, 國立臺灣大學, 醫學工程學研究所碩士論文, 2003. [18] 宮春斐,“新型被動式微混合器之研發”, 國立臺灣大學, 應用力學研究所碩士論文, 2003. [19] 張志彰,“微管道電滲流流場之壓力分佈與混合機制分析”, 國立成功大學,工程科學系碩士論文, 2003. [20] 陳志銘,“週期性電場與壓力場聯合引發之微流動特性的研究”, 國立中興大學, 機械工程學研究所碩士論文, 2003. [21] 詹鈞翔,“微流道流體混合之主動控制實驗”, 國立中興大學, 機械工程學系碩士論文, 2004.
本研究係採用數值模擬方式,探討三維彎曲流道中,不同曲率半徑對於微流道中混合濃度的之變化。管道中的流體係以週期性電場與壓力梯度聯合驅動,工作流體為具有氯化鉀(KCl)電解質的稀水溶液,入口端的左、右邊截面上分別具有高、低濃度各為 0.0002 M、0.0001 M。管長同為1000 μm,管的截面為50 μm × 50 μm,管壁面的電動電位(ζ)等於0.128V。在流道內的平均順向壓力梯度為1000 Pa/m,週期性驅動電場的振幅(E)為4000 V/m,週期性壓力梯度的振幅為2000 Pa/m,兩者的角頻率皆為100 rad/sec,但兩者間的相位差為π。在此條件下,探討在三維彎管微流道中,截面上流場結構的分佈與混合濃度沿流動方向之變化,以及彎管微流道曲率半徑之影響。研究結果顯示:在直管模型中,流體的運動以沿流體前進的方向為主。在彎管流道中,週期性的壓力梯度與電場變化會使在截面上產生左右來回震盪的流場結構,即為本研究之混合機制。隨著曲率半徑的變小,截面上以電場驅動引發之作用力為主,導致截面上左右來回之作用力也越大。因此受到上述混合機制的作用,在相同條件之彎管流道中,受到上述的混合機制作用,曲率半徑變小會提高混合的效率。

This study simulates the microflow characteristics induced by the periodical electrical and pressure fields in streamwise direction in a three-dimensional curved channels. The electrolyte solution is KCl. The properties of the liquid solution are listed as follows. The high and low concentration of electrolyte at the entrance are 0.0002 M、0.0001 M, the length of pipes are 1000 μm with the same cross section 50 μm × 50 μm, zeta potential value ζ= 0.128 V.The applied magnitudes are 4000 V/m for the electrical field and 2000 Pa/m for the pressure gradient with a mean pressure gradient of 2000 Pa/m. The driving frequencies are 100 rad/sec and the phase difference between the electric and pressure fields is set at π . The result shows that in the curved pipe, both the pressure gradient and electric field will create an effect of back and forth flowing characteristic at each section, leading to mixing in curved channels. The magnitudes of the traversing flow at each section is strongly dependent upon the driving electric field, but midly on the pressure gradient. Therefore, as the radius of curvature of the curved channel decrease, the magnitudes of the travering flow becomes strong. This results in an increase in the mixing efficiency.
其他識別: U0005-1008200712080400
Appears in Collections:機械工程學系所

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