Abstract In the present study, the flow and heat transfer characteristics from a horizontal cylinder in crossflow wrapped with whole and segmented layers of metal foams are investigated. High porosity and thermal conductivity metal foam layers are tested with two different thicknesses. The horizontal cylinders are heated with a uniform heat flux and forced convection tests are conducted for Reynolds number range of 7500 – 18000. The angle at which the metal foam segmented layers are positioned against the incoming flow is varied to study the effect of the angle of incidence on the performance. The heat transfer coefficient and pressure drop are measured in order to determine the overall performance factor which relates the enhancement in heat transfer with the pressure drop augmentation. The experimental results showed that all metal foam configurations outperformed the bare cylinder case. The whole layer configuration showed the highest heat transfer enhancement as opposed to the segmented layer case, but with a higher pressure drop. However, the segmented metal foam layer configuration, at an optimum angle of incidence, provided the best heat transfer enhancement with a lower pressure drop, signifying the highest overall performance factor.

中文翻译：

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用整层和分段金属泡沫包裹的水平圆柱体的传热增强

摘要 在本研究中，研究了由整层和分段金属泡沫包裹的横流中水平圆柱体的流动和传热特性。高孔隙率和导热性金属泡沫层以两种不同的厚度进行测试。水平圆柱体以均匀的热通量加热，并针对雷诺数范围为 7500 – 18000 进行强制对流测试。 改变金属泡沫分段层相对于流入流的角度以研究角度的影响表现的发生率。测量传热系数和压降以确定与传热增强与压降增加相关的整体性能因素。实验结果表明，所有金属泡沫配置都优于裸气缸。与分段层的情况相比，整个层配置显示出最高的传热增强，但具有更高的压降。然而，分段泡沫金属层配置在最佳入射角下提供了最佳的传热增强和较低的压降，意味着最高的整体性能因素。