Thermal Convection in Porous Media at High Rayleigh Numbers
Thermal Convection in Porous Media at High Rayleigh Numbers
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DOI：
10.1115/1.4029087
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发表时间：
2015-03
影响因子：
--
通讯作者：
Daniel J. Keene;R. J. Goldstein
中科院分区：
文献类型：
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作者：
Daniel J. Keene;R. J. Goldstein
本文对多孔介质中的热对流进行了实验研究，研究了在高瑞利数下，从下面加热的水平层的传热。在一个充满压缩氩气的立方体容器中使用聚丙烯球填充床，压力在5.6 bar和77 bar之间变化，得到的流体瑞利数在1.68 × 109和3.86 × 1011之间，对应的瑞利-达西数在7.47 × 103和2.03 × 106之间。从多孔介质和均匀流体系统中的瑞利-贝纳德对流的当前和早期研究，薄的热边界层的存在和重要性清楚地表明。除了确定在高瑞利数的热边界层的管理作用，成功的相关性的数据使用均匀的流体无量纲组时，热边界层厚度变得小于与孔隙特征相关的长度尺度。
An experimental study of thermal convection in a porous medium investigates the heat transfer across a horizontal layer heated from below at high Rayleigh number. Using a packed bed of polypropylene spheres in a cubic enclosure saturated with compressed argon, the pressure was varied between 5.6 bar and 77 bar to obtain fluid Rayleigh numbers between 1.68 × 109and 3.86 × 1011, corresponding to Rayleigh–Darcy numbers between 7.47 × 103and 2.03 × 106. From the present and earlier studies of Rayleigh–Benard convection in both porous media and homogeneous fluid systems, the existence and importance of a thin thermal boundary layer are clearly demonstrated. In addition to identifying the governing role of the thermal boundary layer at high Rayleigh numbers, the successful correlation of data using homogeneous fluid dimensionless groups when the thermal boundary layer thickness becomes smaller than the length scale associated with the pore features is shown.