Fukuda Takashi, Harada Makoto Ryo
Department of Materials and Chemistry, National Institute of Advanced Industrial Science and Technology, 4-2-1, Nigatake, Miyagino-ku, Sendai 983-8551, Japan.
Micromachines (Basel). 2021 Dec 18;12(12):1580. doi: 10.3390/mi12121580.
We conducted a theoretical investigation of the cross-sectional aspect ratio of a rectangular channel to have sufficiently low frictional resistance under less than 150 of the Reynolds number. From the theoretical consideration, it was clarified that 3.40 or more is recommended as a criterion for determining the aspect ratio. This addresses the problem of determining the interval of rectangle channels, installed in a plate reactor. There is a concern that the real system does not follow the analytical solution, assuming laminar flow, since the higher aspect ratio leads to disturbances of the flow such as the emergence of vortices. However, in the channel's volume range of ( × × ) = (7.0 mm × 0.38 mm × 0.26 m), such a turbulence was not observed in the detailed numerical calculation by CFD, where both calculation results were in agreement to within 3% accuracy. Moreover, even in an experimental system with a surface roughness of ca. 7%, friction resistance took agreement within an accuracy of ±30%.
我们对矩形通道的横截面纵横比进行了理论研究，目的是在雷诺数小于150的情况下使摩擦阻力足够低。从理论考虑可知，建议将3.40或更大的值作为确定纵横比的标准。这解决了确定安装在板式反应器中的矩形通道间距的问题。有人担心实际系统并不遵循假设为层流的解析解，因为较高的纵横比会导致流动出现扰动，如漩涡的出现。然而，在通道体积范围为(××) = (7.0毫米×0.38毫米×0.26米)时，在通过计算流体动力学（CFD）进行的详细数值计算中未观察到这种湍流，两个计算结果的精度在3%以内相符。此外，即使在表面粗糙度约为7%的实验系统中，摩擦阻力在±30%的精度范围内也相符。
