EXPERIMENTAL STUDY ON HEAT TRANSFER PERFORMANCE AND FLOW VISUALIZATION IN MICROCHANNELS WITH MICROPILLARS

EXPERIMENTAL STUDY ON HEAT TRANSFER PERFORMANCE AND FLOW VISUALIZATION IN MICROCHANNELS WITH MICROPILLARS

Článek WoS

This research investigated heat transfer performance and flow characteristics of three polydimethylsiloxane microchannels full of deionised water as a working fluid. A single micropillar, horizontal micropillars, and vertical micropillars along the flow direction were prepared on the microchannels experimentally. Re-sults show that the Nusselt number of microchannels with two horizontal mi-cropillars is 19% higher than that with a single micropillar. The microchannel with two vertical micropillars has the Nusselt number is 29% higher than that with a single micropillar, which shows the best performance on the heat transfer enhancement. Visualization experiments of the flow field were carried out to ex-plore the enhanced mechanism of the heat transfer for microchannels with vari-ous micropillar arrangements. When the flow rate is 7 mLpm, the maximum ve-locities near the single cylinder and the horizontal micro-column are 0.5 m/s and 0.52 m/s. Fluid velocity in a region between two vertical micropillars reaches 0.72 m/s when the flow rate is 7 mLpm. The fluid in the high-speed region is fully mixed around the micropillar, which reduces the stagnation region area down-stream of the vertical micropillar and enhances heat transfer. © 2022 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, Belgrade, Serbia. This is an open access article distributed under the CC BY-NC-ND 4.0 terms and conditions.

This research investigated heat transfer performance and flow characteristics of three polydimethylsiloxane microchannels full of deionised water as a working fluid. A single micropillar, horizontal micropillars, and vertical micropillars along the flow direction were prepared on the microchannels experimentally. Re-sults show that the Nusselt number of microchannels with two horizontal mi-cropillars is 19% higher than that with a single micropillar. The microchannel with two vertical micropillars has the Nusselt number is 29% higher than that with a single micropillar, which shows the best performance on the heat transfer enhancement. Visualization experiments of the flow field were carried out to ex-plore the enhanced mechanism of the heat transfer for microchannels with vari-ous micropillar arrangements. When the flow rate is 7 mLpm, the maximum ve-locities near the single cylinder and the horizontal micro-column are 0.5 m/s and 0.52 m/s. Fluid velocity in a region between two vertical micropillars reaches 0.72 m/s when the flow rate is 7 mLpm. The fluid in the high-speed region is fully mixed around the micropillar, which reduces the stagnation region area down-stream of the vertical micropillar and enhances heat transfer. © 2022 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, Belgrade, Serbia. This is an open access article distributed under the CC BY-NC-ND 4.0 terms and conditions.

Heat transfer enhancement; Microchannel; Micropillar; Particle image velocimetry; Stagnation region

Heat transfer enhancement; Microchannel; Micropillar; Particle image velocimetry; Stagnation region

Ye M., Yan T., Wang J., He Y., Klemeš J.J.

2023

23.04.2022

VINČA Institute of Nuclear Sciences

Mike Petrovića Alasa 12, 11000 Belgrade, Vinča, Serbia

0354-9836

Thermal Science

5

25

Srbská republika

4169

4178

10

http://www.doiserbia.nb.rs/img/doi/0354-9836/2022/0354-98362205169Y.pdf