Influences of geometric parameters on flow characteristics of rectangular microchannels
Hou Yali1,2, Wang Jianwen1,2
1.College of Energy and Power Engineering, Inner Mongolia University of Technology, Hohhot, Inner Mongolia 010051 China; 2.Inner Mongolia Key Laboratory of Reproducible Energy, Hohhot, Inner Mongolia 010051, China
Abstract:The flow characteristics of eight rectangular microchannels with different geometric parameters are measured when distilled water is used as a working fluid. The relationship between friction factor or Poisuille number and Reynolds number is obtained, further the influences of hydraulic diameter, the ratio of height to width, and the ratio of channel length to hydraulic diameter on flow characteristics are analysed. The results show that the friction factor and Poisuille number increase with the decreasing hydraulic diameter and length-to-hydraulic diameter ratio at the same height-to-width ratio. For the microchannels with nearly the same length-to-hydraulic diameter ratio but different height-to-width ratio, the friction factor and Poisuille number grow with the reducing height-to-width ratio. Specially, in the range of variation of parameters interested in our study, the influence of height-to-width ratio is more denominated than the other geometric parameters. Hence the friction factor of rectangular microchannels is a complicated function of hydraulic diameter, height-to-width ratio and length-to-hydraulic diameter ratio.
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