Bubble dynamics and flow boiling characteristics in three different microchannel configurations

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• 作者：Yogesh K. Prajapati^a ; Manabendra Pathak^b ; ^{mpathak@iitp.ac.in} ; Mohd Kaleem Khan^b
• 关键词：Flow boiling ; Bubble dynamics ; Flow reversal ; Segmented finned microchannels ; Flow instability
• 刊名：International Journal of Thermal Sciences
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：112
• 期：Complete
• 页码：371-382
• 全文大小：2447 K
• 卷排序：112

文摘

Flow boiling experiments have been performed to compare bubble growth and flow instabilities in uniform, diverging and segmented finned microchannels. Experiments have been conducted in an array of 12 microchannels with 522 μm hydraulic diameter in each configuration. Deionized water has been used as coolant and investigation has been made for coolant mass flux range of 100–350 kg/m2s and heat flux range of 10–350 kW/m2. Flow visualization has been performed to analyze bubbles growth, their coalescence and motion in each microchannel configuration. A comparative study of bubble growth phenomena in all three channel configurations has been presented. The role of bubble dynamics on flow instability has been discussed. Bubble growth pattern in segmented channel is completely different than that in uniform and diverging cross-section channels. Bubbles are characterized with multiple growing interfaces and suppressed growth along the upstream direction of coolant flow. The suppressed growth of bubble slug in segmented finned reduces flow reversal and subsequent instabilities in flow boiling.