Heat transfer from a cylinder in a porous medium subjected to axial flows.
Heat transfer from a cylinder in a porous medium subjected to axial flows.
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受轴向流影响的多孔介质中圆柱体的传热。
DOI：
10.1299/kikaib.56.1095
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Hiroyuki Nigorinuma
中科院分区：
文献类型：
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作者：
S. Kimura;Hiroyuki Nigorinuma
对置于多孔介质中的轴向自然流动和强迫流动的等温圆柱体的换热进行了实验研究。初步分析表明，圆柱体的自然对流换热和强迫对流换热均可描述为平板问题的摄动情形。ξ=L/a√(Ra)和ζ=L/a√(Pe)分别代表曲率效应，作为自然流动和强迫流动的参数。热传递速率相对于平板壳体的偏差被描述为ξ或ζ的函数。使用玻璃微珠和水的多孔层，测量了三种不同尺寸的微珠直径下圆柱体的传热率。实验结果与理论预测吻合较好，一般情况下，努塞尔数除以√(Ra)或√(Pe)随ξ或ζ的增大而增大。
Heat transfer from an isothermal cylinder placed in a porous medium and subjected to natural or forced flows in the axial direction has been studied experimentally. It is shown in a preliminary analysis that both natural and forced convective-heat transfer from the cylinder may be described as a perturbed case from a flat-plate problem. ξ=L/a√(Ra) and ζ=L/a√(Pe), each representing the curvature effect, serve as the parameters for natural and forced flow, respectively. The departure of the heat transfer rate relative to a flat-plate case is described as a function of ξ or ζ. Using a porous layer of glass beads and water, heat transfer rates from the cylinder are measured for three different sizes of bead diameters. The experimental results agree well with the theoretical predictions; the Nusselt numbers divided by √(Ra) or √(Pe), in general, increase as ξ or ζ increases.