中国物理B ›› 2002, Vol. 11 ›› Issue (3): 226-232.doi: 10.1088/1009-1963/11/3/305

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Numerical simulation of dispersion generated by a 180° turn in a microchannel

C. T. Culbertson1, J. M. Ramsey1, 姚朝晖2, G. L. Yoder3   

  1. (1)Chemical and Analytical Sciences Division, Oak Ridge National Laboratory P.O. Box 2008, Oak Ridge, Tennessee 37831-6142, USA; (2)Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China; Engineering Technology Division, Oak Ridge National Laboratory, P.O. Box 2009, Oak Ridge, Tennessee 37831-8045, USA; (3)Engineering Technology Division, Oak Ridge National Laboratory, P.O. Box 2009, Oak Ridge, Tennessee 37831-8045, USA
  • 收稿日期:2001-07-11 修回日期:2001-11-18 出版日期:2002-03-13 发布日期:2005-06-13
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 19902009).

Numerical simulation of dispersion generated by a 180° turn in a microchannel

Yao Zhao-Hui (姚朝晖)ab,  G. L. Yoderb, C. T. Culbertsonc, J. M. Ramseyc   

  1. a Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China; b; Engineering Technology Division, Oak Ridge National Laboratory, P.O. Box 2009, Oak Ridge, Tennessee 37831-8045, USA; c Chemical and Analytical Sciences Division, Oak Ridge National Laboratory P.O. Box 2008, Oak Ridge, Tennessee 37831-6142, USA
  • Received:2001-07-11 Revised:2001-11-18 Online:2002-03-13 Published:2005-06-13
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 19902009).

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摘要： A numerical scheme is developed to simulate electro-osmotic flow and mass transport in a microchannel which includes a 180° turn. The model has been used to predict the behaviour of electro-osmotically driven flows. The detailed structure of the flow field in a microchannel in combination with species mass diffusion can explain the concentration dispersion introduced by a 180° turn. The results of our simulations agree both qualitatively and quantitatively with experimental observation. It is demonstrated that an improved electro-osmotic force model could simulate the electrokinetically driven flow well without making detailed calculations of the electric charge density distribution within the electrical double layer. Additionally, because this model applies forces to the liquid as opposed to imposing local velocities, it should also be appropriate for use where pressure gradients exist in the flow field.

Abstract: A numerical scheme is developed to simulate electro-osmotic flow and mass transport in a microchannel which includes a 180° turn. The model has been used to predict the behaviour of electro-osmotically driven flows. The detailed structure of the flow field in a microchannel in combination with species mass diffusion can explain the concentration dispersion introduced by a 180° turn. The results of our simulations agree both qualitatively and quantitatively with experimental observation. It is demonstrated that an improved electro-osmotic force model could simulate the electrokinetically driven flow well without making detailed calculations of the electric charge density distribution within the electrical double layer. Additionally, because this model applies forces to the liquid as opposed to imposing local velocities, it should also be appropriate for use where pressure gradients exist in the flow field.

Key words: surface chemistry, molecular diffusion, numerical simulation, microchannel

中图分类号:  (Diffusion and thermal diffusion)

  • 66.10.C-
82.45.-h (Electrochemistry and electrophoresis)