Analysis of Aspect Ratio in a Miniature Rectangle Channel for Low Frictional Resistance

Takashi Fukuda, Makoto Ryo Harada
2021 Micromachines  
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
more » ... ytical 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 (W × H × L) = (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%.
doi:10.3390/mi12121580 pmid:34945430 pmcid:PMC8707677 fatcat:jiimac6ol5ek7dhbn7lnaeu4f4