Journal of Mechanical Science and Technology

, Volume 19, Issue 1, pp 199–208 | Cite as

Enhancement of stirring in a straight channel at Low Reynolds-numbers with various block-arrangement

  • Hyeung Seok Heo
  • Yong Kweon Suh


In this study a newly designed microchannel as an efficient fluid-mixer is proposed. This design is comprised of a channel and a series of blocks periodically attached on the bottom surface of the channel. In this configuration, the stirring is greatly enhanced at a certain range of parametric values. To characterize the flow field and the stirring effect, both numerical and experimental methods were employed. To obtain the velocity field, three-dimensional numerical computation to the Navier Stokes equations was performed by using a commercial code, FLUENT 6.0. The fluid-flow solutions were then cast into studying the characteristics of stirring with the aid of Lyapunov exponent. In this study, the Lyapunov exponents were computed manually because the commercial code does not provide the corresponding tool. In the experiment, flow visualization was performed by using pure glycerin in a tank and glycerin mixed with small amount of a fluorescent dye in the other tank. The numerical results show that the pattern of the particles’ trajectories in the microchannel heavily depends on the block arrangement. It was shown that the stirring is significantly enhanced by a larger block-height and reaches maximum when the height is 0.8 times the channel width. We also studied the effect of the block stagger angle. It was found that stirring performance is the best at the block stagger angle of 45°.

Key Words

MEMS Micro Mixer Lyapunov Exponent 


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Copyright information

© The Korean Society of Mechanical Engineers (KSME) 2005

Authors and Affiliations

  1. 1.Department of Mechanical Engineering Dong-A UniversitySaha-gu, BusanKorea

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