Low Reynolds numbers convective heat transfer enhancement in roughened microchannels. (March 2020)

• Record Type: Journal Article
• Authors: Hsieh, Shou-Shing; Hsieh, Yu-Cheng; Hsu, Ya-Chiao; Huang, Ching-Feng
• Is Part Of: International communications in heat and mass transfer. Volume 112(2020:Mar.)
• Publication Date: 2020-03
• Subjects: Heat transfer enhancement -- Convective microchannel flow -- Pin-fin roughened surface -- Axial wall heat conduction; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Heat -- Transmission; Mass transfer; Periodicals; 621.4022
• DOI: 10.1016/j.icheatmasstransfer.2020.104486
• Languages: English
• ISSNs: 0735-1933

Abstract

Abstract: Heat transfer enhancement studies were conducted on a variety of roughened microchannels for a laminar flow at 3≦ Re ≦25 with DI water as the cooling fluid. Five different discrete roughened surfaces, which were circular, square, triangular, elliptical, and hexagonal in shape, were used in the test channels with a channel cross-sectional area aspect (height to width) ratio of 0.25. The smooth-surface channel had a length of 30 cm, width of 200 μm, and height of 50 μm, which creates the hydraulic diameter of 80 μm for the study. A constant heat flux of 1.25 W/cm 2 was applied to the bottom of the channel through the ITO surface. Results of the cooling performance in terms of the enhancement factor compared to those of a smooth channel found that the square pin-fin roughened surfaces had the best transfer enhancement followed by the ellipse, circle, hexagon, and triangle as compared to that of a smooth surface. Furthermore, axial wall heat conduction was noted for both smooth and roughened channels. Highlights: Convective heat transfer enhancement in five different roughened microchannels. Exploring the phenomenon of conjugate heat transfer in microchannels. Heat transfer enhancement effect of microchannels at low Reynolds number.