Study on micro meniscus behavior in the capillary evaporator of a loop heat pipe

2016 Fiscal Year Final Research Report

• Project/Area Number: 15H06287
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Thermal engineering
• Research Institution: Toyohashi University of Technology
• Principal Investigator: Nishikawara Masahito 豊橋技術科学大学, 工学(系)研究科(研究院), 助教 (50757367)
• Project Period (FY): 2015-08-28 – 2017-03-31
• Keywords: ループヒートパイプ / 三相界線 / 気液二相流 / 蒸発メニスカス / 可視化 / 最適化 / 蒸発器設計方法

Outline of Final Research Achievements

To develop design method for the capillary evaporator shape in a loop heat pipe, this study observed thermo-fluid behavior in the evaporator and developed a numerical model for heat transfer of the evaporator taking meniscus at a three-phase contact line (TPCL) within the case, wick, and grooves into account and a method to optimize wick shape in the evaporator. The meniscus at the TPCL was observed by developed the visualization evaporator using a quartz glass tube during the LHP operation and the meniscus oscillated with size amplitude of 10-400 μm at a steady state. The developed numerical model showed that evaporator heat-transfer coefficient increased with 80 % when the meniscus was taken into account. The developed optimization method was validated with the experimental results and the evaporator heat-transfer coefficient reached a local maximum in terms of the TPCL length.

Free Research Field

熱工学