Enhancement of Phase Change Heat Transfer on Micro-structured Surface and Application to Micro Heat Pipe

2015 Fiscal Year Final Research Report

• Project/Area Number: 25871042
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Thermal engineering; Nano/Microsystems
• Research Institution: Ube National College of Technology
• Principal Investigator: Tokunaga Atsushi 宇部工業高等専門学校, 機械工学科, 准教授 (20609797)
• Co-Investigator(Renkei-kenkyūsha): TSURUTA TAKAHARU 九州工業大学, 大学院工学研究院機械知能工学研究系, 教授 (30172068) ; NAGAYAMA GYOKO 九州工業大学, 大学院工学研究院機械知能工学研究系, 准教授 (60370029)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 熱工学 / 滴状凝縮 / 機能性伝熱面 / MEMS / 伝熱促進 / 濡れ性こう配

Outline of Final Research Achievements

The micro- and nano-scale phase change phenomena become more important because recent MEMS technologies enable us to create new surface structures for high heat flux devices. In the condensation heat transfer, it is well known dropwise condensation on a hydrophobic surface has a larger heat transfer coefficient than filmwise condensation. Larger droplets in ordinary systems depart from the condensing surface by the gravity or the vapor shear-flow and the bare surface is created for the rapid condensation. But, those forces cannot be expected in the micro- and nano-systems. In order to realize enhancement of condensation heat transfer, it is necessary to develop new method for removing the larger droplets from the condensing surface. In this study, the micro- structures with wettability gradient are fabricated as the hydrophobic-hydrophilic surfaces. It is found that the condensation heat flux on the micro-structured surface can be enhanced due to its drainage ability.

Free Research Field

熱工学