Clarification of determining mechanism of internal flow behavior and improvement of operating characteristics of oscillating heat pipes

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K03906
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 19020:Thermal engineering-related
• Research Institution: Japan Aerospace EXploration Agency
• Principal Investigator: Ando Makiko 国立研究開発法人宇宙航空研究開発機構, 研究開発部門, 主任研究開発員 (60748094)
• Co-Investigator(Kenkyū-buntansha): 永井 大樹 東北大学, 流体科学研究所, 教授 (70360724)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 自励振動型ヒートパイプ / 逆止弁 / 循環流

Outline of Final Research Achievements

To improve the thermal performance of oscillating heat pipes (OHPs), it is necessary to make the internal flow circulating rather than oscillatory. In this study, we focused on the effect of flow resistance of a check valve. The correlation between flow resistance and internal flow was systematically clarified, and the desirable conditions of check valves were suggested for maximizing the thermal performance of OHPs. In addition, a rectifying mechanism with no-moving parts was investigated and evaluated as an alternative to the conventionally used floating-type check valves. As a result, it was experimentally demonstrated that a very simple method called “interconnecting channel” (diagonal bypass channel connecting adjacent channels) can significantly improve the thermal performance of OHPs.

Free Research Field

熱工学

Academic Significance and Societal Importance of the Research Achievements

電子機器の高機能・高性能化に伴う高発熱化に伴い，その排熱手段は業界共通の大きな課題である．逆止弁付き自励振動型ヒートパイプは高い熱輸送性能を持ち，狭い隙間からも排熱可能であるが，逆止弁の流動特性が内部流動に及ぼす影響については，これまで体系的に整理されていなかった．本研究で逆止弁の流動抵抗／レイアウトと自励振動型ヒートパイプの内部流動／熱輸送性能の相関を明らかにし，それに基づいて望ましい逆止弁の条件を定量的に示したことは，今後の自励振動型ヒートパイプの設計指針となる意義深いものである．また，より簡易な整流機構による熱輸送性能向上についても実現可能性を示した．