Heat Transfer Enhancement at Nanostructured Surface in Parallel-plate Microchannel
Heat Transfer Enhancement at Nanostructured Surface in Parallel-plate Microchannel
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DOI：
10.1007/978-3-540-76694-0_185
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
Gyoko Nagayama;Seishi Sibuya;M. Kawagoe;T. Tsuruta
中科院分区：
文献类型：
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作者：
Gyoko Nagayama;Seishi Sibuya;M. Kawagoe;T. Tsuruta
在本文中，我们研究的影响，纳米结构的平行板微通道流动的实验以及纳米通道流动的分子动力学研究的基础上。在实验中，使用电镀和蚀刻的微通道表面涂覆有纳米结构，并且纳米结构的尺寸与常规的表面粗糙度相当不同。平行板微通道的间距为300 µm，远小于其宽度和长度，以减少侧壁的影响，这是一种经过充分研究的几何形状。结果表明，大接触角（疏水性）的纳米结构表面的摩擦常数比小接触角（疏水性）的表面低。在纳米结构特征尺寸为200- 700 nm的亲水性纳米结构表面上也获得了较高的传热系数。在纳米通道流动的分子动力学模拟中，发现固液界面的边界条件都依赖于表面润湿性。界面热阻在纳米结构的表面和显着的传热增强已实现在纳米结构的表面的韧性。虽然具有纳米结构的表面具有比平坦表面更大的表面积，但是由纳米结构引起的热通量增加的速率仍然是显著的;然而，尚不清楚纳米结构的效果是否可以在微通道实验中检测到。
In this paper, we examine the effect of the nanostructures on the parallel-plate microchannel flow experimentally as well as the nanochannel flow based on molecular dynamic studies. In the experiments, the microchannel surface is coated with nanostructures using plating and etching, and the sizes of nanostructures are rather different from the conventional surface roughness. The spacing of the parallel-plate microchannel is 300 µm, which is much smaller than its width and length, in order to reduce the effects of sidewalls as a well-studied geometry. It is found that the friction constant for the nanostructured surfaces of large contact angle (hydrophobility) is low compared with the surfaces of small contact angle (hydrophility). Also, the higher heat transfer coefficients have been obtained at the hydrophilic nanostructured surface with characteristic size of nanostructure of 200–700nm. In the molecular dynamics simulations of nanochannel flow, it is found that both the boundary condition at the solid-liquid interface depend on the surface wettability. The interface thermal resistance decreases at the nanostructured surface and significant heat transfer enhancement has been achieved at the nanostructured surfaces of hydrophility. Although the surface with nanostructures has larger surface area than the flat surface, the rate of heat flux increase caused by the nanostructures is still remarkable; however, it is unclear if the effect of the nanostructures could be detected in the microchannel experiments.