Heat Transfer from an Oxidized Large Copper Surface to Liquid Helium: Dependence on Surface Orientation and Treatment
Heat Transfer from an Oxidized Large Copper Surface to Liquid Helium: Dependence on Surface Orientation and Treatment
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从氧化的大铜表面到液氦的热传递：对表面取向和处理的依赖
DOI：
10.1007/978-1-4613-0373-2_28
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
J. Yamamoto
中科院分区：
文献类型：
--
作者：
A. Iwamoto;T. Mito;K. Takahata;N. Yanagi;J. Yamamoto
本文测量了液氦中大铜板（18 × 76 mm）的传热与传热面取向和处理的关系。这些结果与大尺度超导体的应用有关。为了阐明表面处理剥离的区域的影响，我们研究了五种类型的传热表面区域，包括：（a）100%抛光的铜样品，（B）和（c）两种具有不同氧化模式的50%氧化铜样品，（d）75%氧化铜样品，（e）90%氧化铜样品，和（f）100%氧化铜样品。我们观察到，临界热流密度取决于传热表面的取向。临界热通量在0°-30 °的角度处最大，并且随着角度大于30°而单调减小，其中角度是参考水平轴取的。另一方面，最小热通量较少依赖于表面取向。超过75%的表面氧化使临界热流密度增加。50%和90%氧化Cu样品的最小热通量与100%氧化Cu样品的最小热通量大致一致。实验和计算表明，临界热流密度和最小热流密度是氧化表面积分数的双线性函数。
Heat transfer of large copper plates (18 × 76 mm) in liquid helium has been measured as a function of orientation and treatment of the heat transfer surface. The results relate to applications of large scale superconductors. In order to clarify the influence of the area where the surface treatment peels off, we studied five types of heat transfer surface areas including: (a) 100% polished copper sample, (b) and (c) two 50% oxidized copper samples having different patterns of oxidation, (d) 75% oxidized copper sample, (e) 90% oxidized copper sample, and (f) 100% oxidized copper sample. We observed that the critical heat flux depends on the heat transfer surface orientation. The critical heat flux is a maximum at angles of 0° – 30° and decreases monotonically with increasing angles above 30°, where the angle is taken in reference to the horizontal axis. On the other hand, the minimum heat flux is less dependent on the surface orientation. More than 75% oxidation on the surface makes the critical heat flux increase. The minimum heat fluxes of the 50 and 90% oxidized Cu samples approximately agree with that of the 100% oxidized Cu sample. Experiments and calculations show that the critical and the minimum heat fluxes are a bilinear function of the fraction of oxidized surface area.