Abstract Application of different heat transfer augmentation techniques, including the use of fins or foams, were investigated to enhance the melting rate of a solid phase change material within an annulus where the inner and outer pipes were subjected to constant wall temperature. The carbon fibre fins as well as three commonly-used foams (made of three different materials: nickel, aluminium and copper) were simulated. Firstly, keeping the total fin volume constant, the fin number density effect on the melting rate was investigated. After an optimal fin number density was obtained, three possible strategies (unequal length, uneven intervals and tree-shaped fins) were explored aimed at a more comprehensive understanding of the induced heat transfer enhancement. It was observed that with a fixed fin thickness and volume, the melting time is not a monotonic function of the fin number density and can be optimized. Comparing pure PCM melting, the use of optimized fin number reduced over 60% of melting time, while additional 8% and 4% further time reduction could be achieved by appropriately increasing lengths and decreasing intervals of bottom fins, respectively. The use of tree-like fins resulted in a longer melting time, comparing to that of longitudinal straight fins, which indicates it is not always a good option. Finally, the results, primarily the melting rates, were compared with those obtained through the use of metal foams with different metals. It was observed that the melting time of optimized strategy-1 is rather less than those of Cu and Al foams, and approximately 2200s shorter than that of Ni foams. These results indicate that the fins, if designed properly, can be as efficient as foams.

中文翻译：

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具有内外翅片和金属泡沫的环形外壳中PCM熔化性能增强的数值研究

摘要 研究了不同传热增强技术的应用，包括使用翅片或泡沫，以提高内管和外管承受恒定壁温的环形空间内固体相变材料的熔化速率。模拟了碳纤维翅片以及三种常用的泡沫材料（由三种不同的材料：镍、铝和铜制成）。首先，保持总翅片体积不变，研究翅片数密度对熔化速率的影响。在获得最佳翅片数密度后，探索了三种可能的策略（不等长、不均匀间隔和树形翅片），旨在更全面地了解诱导传热增强。据观察，在固定翅片厚度和体积的情况下，熔化时间不是翅片数密度的单调函数，可以优化。与纯 PCM 熔化相比，使用优化的翅片数量减少了 60% 以上的熔化时间，而通过适当增加底部翅片的长度和减少间隔，分别可以进一步减少 8% 和 4% 的时间。与纵向直翅片相比，使用树状翅片导致更长的熔化时间，这表明它并不总是一个好的选择。最后，将结果，主要是熔化速率，与通过使用不同金属的金属泡沫获得的结果进行比较。观察到优化策略 1 的熔化时间比泡沫铜和泡沫铝短，比泡沫镍短约 2200 秒。这些结果表明，鳍，