TY - JOUR
TI - Experimental study on heat transfer performance and flow visualization in microchannels with micropillars
AU - Ye Mingzheng
AU - Yan Tingxiang
AU - Wang Jin
AU - He Yongqing
AU - Klemeš Jiří Jaromír
JN - Thermal Science
PY - 2022
VL - 26
IS - 5
SP - 4169
EP - 4178
PT - Article
AB - 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. Results show that the Nusselt number of microchannels with  two horizontal micropillars 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 explore the enhanced mechanism of the  heat transfer for microchannels with various micropillar arrangements. When  the flow rate is 7 mLpm, the maximum velocities 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.