Basic Research on the Heat Transfer Augmentation with High Performance by the Micro-Scale Concave-Convex Surfaces

微尺度凹凸表面高性能强化传热基础研究

• 批准号: 10650197
• 负责人: NARIAI Hideki
• 金额: $ 2.56万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650197/
• 关键词: micro-scale; concave-convex surface; ultra small scale; drug reduction; heat transfer; solid-liquid interface; molecular dynamics; surface energy; はつ水性; 表面自由エネルギー; 4フッ化エチレン; 高機能面

As a basic research to realize the heat transfer augmentation with high performance by using the heat transfer surface with nano-meter to micron-scale concave-convex structure, present research is aimed at pursuing the possibility of drag reduction and heat transfer augmentation in these surfaces, and making clear the mechanism. At first, experiments were conducted on the drag reduction. The drag reduction was observed by maximally 10 % with the ultra small scale concave-convex surface, and further the drag reduction by almost 5% was confirmed with smooth water-repellent surface with hydrophobic coating. As a second step research, experiments on the forced convection heat transfer with ultra small scale surfaces were conducted. The temperature distributions by several ゜C higher than the predictions assuming smooth surface were derived and it was estimated that there was the thermal resistance on the surface. The existence of the air layer at the solid-liquid interface where the surface energy is low was estimated as the reason. As a theoretical research on the drug reduction on the surfaces with ultra small scale concave-convex and hydrophobic coating, molecular dynamics simulation has been conducted based upon a hypothesis that boundary slip can occur if solid-liquid intraction is weakened. The analysis is to study the boundary slip in Couette flow of Lennard-Jones fluid confined by two walls apart by about 20 times of molecular diameter. The results shows the ship when Lennard-Jones parameter for energy depth are given by a factor of 0.1 or 0.5 compared with the parameter for liquid-liquid interaction. As shown above, the new results on the heat transfer augmentation on the surfaces with ultra small scale surfaces have been derived experimentally and theoretically.

作为利用纳米到微米尺度凹凸结构的传热表面实现高性能增热的基础研究，本研究旨在探索这些表面减阻增热的可能性，并明确其机理。首先进行了减阻实验。采用超小尺寸凹凸表面，可最大减少10%的阻力；采用光滑的疏水表面，可进一步减少近5%的阻力。作为第二步研究，进行了超小尺度表面强制对流换热实验。假设获得光滑表面，温度分布比预测高几个C，并且估计表面上存在热阻。估计其原因在于固液界面存在空气层，表面能较低。作为超小尺度凹凸疏水涂层表面药物还原的理论研究，基于固液相互作用减弱会发生边界滑移的假设，进行了分子动力学模拟。分析的目的是研究两壁相距约20倍分子直径的Lennard-Jones流体在Couette流动中的边界滑移。结果表明，船舶在Lennard-Jones参数下的能量深度比液-液相互作用参数下的能量深度大0.1或0.5倍。如上所示，我们从实验和理论两方面推导出了关于超小尺度表面传热强化的新结果。

项目成果

M.Hasegawa et al.: "Drag Reduction & Thermal Behavior of Nanoscale Concave-Convex Surfaces"Thermal Science & Engineering. Vol.7,No.6. 133-138 (1999)

M.Hasekawa 等人：“减阻

M. Hasegawa, et al.: "Drag Reduction on Microscale Concave-Convex Surface"Proc. ASME Heat Transfer Div.. Vol. 364-1. 317-322 (1999)

M. Hasekawa 等人：“微尺度凹凸表面上的阻力减少”Proc。

M. Hasegawa, et al.: "Drag Reduction & Thermal Behavior of Nanoscale Concave-Convex Surfaces"Thermal Science & Engineering. Vol.7, No.6. 133-138 (1999)

M. Hasekawa 等人：“减阻

長谷川雅人,矢部彰,成合英樹 他: "超微細凹凸面による流動抵抗変化に関する研究" 日本伝熱シンポジウム講演論文集. Vol.3. 689-690 (1998)

Masato Hasekawa、Akira Yabe、Hideki Narigo 等：“超细凹凸表面引起的流动阻力变化的研究”日本传热研讨会论文集第 3 卷 689-690 (1998)。

M.Hasegawa et al.: "Drag Reduction on Microscale Concave-Convex Surface"Proc. ASME Heat Transfer Div.. Vol.364-1. 317-322 (1999)

M.Hasekawa 等人：“微尺度凹凸表面上的阻力减少”Proc。