Measurement of thermal accommodation coefficients using a simplified system in a concentric sphere shells configuration
Measurement of thermal accommodation coefficients using a simplified system in a concentric sphere shells configuration
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使用同心球壳配置中的简化系统测量热调节系数
DOI：
10.1116/1.4901011
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
T. Niimi
中科院分区：
文献类型：
--
作者：
H. Yamaguchi;Takamasa Imai;T. Iwai;A. Kondo;Y. Matsuda;T. Niimi
对于微尺度的热传递，气体和固体表面之间的相互作用的特征在于热适应系数，并且由于小尺寸的结果而存在的大的表面与体积比是重要的。然而，在微器件中经常使用的非金属表面上的热适应系数的数据很少。在这项研究中，提出了一种新的简化系统在球对称配置，实现了低成本的测量的金属和非金属表面的热适应系数。在球形真空室的中心放置加热器上的微小平板样品，在基于低压法的同心球壳几何假设下测量和分析了导热热流密度。在近自由分子流和过渡流两种流型下，采用近似的热流密度关系式进行测量。所提出的新的测量系统进行了验证…
For heat transfer in the microscale, the interaction between the gas and the solid surface is characterized by the thermal accommodation coefficient, and is important owing to the large surface-to-volume ratio existing as a consequence of the small size. However, there are few data of the thermal accommodation coefficients on the nonmetal surfaces often employed in microdevices. In this research, a novel simplified system in a spherically symmetric configuration is proposed, achieving a low-cost measurement of the thermal accommodation coefficient for both metal and nonmetal surfaces. Tiny flat-plate samples on a heater are placed at the center of a spherical vacuum chamber, and the conductive heat flux is measured and analyzed under the assumption of a concentric spherical shells geometry based on the low-pressure method. An approximate relation for the heat flux is also employed to measure under the near free-molecular and the transitional flow regimes. The proposed novel measurement system is validated...