Experimental visualization of liquid slug dynamics in a meander-shaped low-fill heat pipe using neutron radiography

麓 耕二*; 大久保 建斗*; 大島 章太朗*; 畑本 明彩未*; 栗田 圭輔  ; 原山 勲  ; 飯倉 寛  

Fumoto, Koji*; Okubo, Kento*; Oshima, Shotaro*; Hatamoto, Asami*; Kurita, Keisuke; Harayama, Isao; Iikura, Hiroshi

Self-heating in electronic devices and machinery poses a critical challenge for thermal management. To address this issue, we developed a Meander-Shaped Low-Fill Heat Pipe (MLFHP) as a novel cooling solution. The MLFHP, fabricated from aluminum alloy and filled with water as the working fluid, features a serpentine microchannel structure that enables effective heat transport even at a filling ratio as low as 10 vol.%. Although previous studies have demonstrated its superior thermal performance compared to conventional cooling systems, including pulsating heat pipes (PHPs), the internal flow and heat transfer mechanisms remain unclear. In this study, we employed neutron radiography to non-invasively visualize the working fluid behavior inside the MLFHP during operation. This paper presents the results of the visualization experiments and offers new insights into the unique thermal transport mechanism of the MLFHP.