Open cell metal foam offers an interesting combination of materials properties from a heat exchanger point of view such as a high specific surface area, tortuous flow paths for flow mixing and low weight. A heat exchanger design with metal foams is studied in this work, aimed at low airside pressure drop. It consists of a single row of Al tubes covered with thin layers (4-8 mm) of metal foam. Through wind tunnel testing the impact of various parameters on the thermo-hydraulic performance was considered, including the Reynolds number, the tube spacing, the foam height and the type of foam. The results indicated that if a good metallic bonding between the foam and the tubes can be achieved, metal foam covered tubes with a small tube spacing, small foam heights and made of foam with a high specific surface area potentially offer strong benefits at higher air velocities (> 4 m/s) compared to helically finned tubes. The bonding was done by conductive epoxy glue and was found to have a strong impact on the final results, showing a strong need for a cost-effective and efficient brazing process to connect metal foams to the tube surfaces.
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机译：从热交换器的角度来看，开孔金属泡沫可提供有趣的材料性能组合，例如高比表面积，用于流动混合的曲折流动路径和低重量。在这项工作中，研究了一种采用金属泡沫的热交换器设计，旨在降低空气侧的压降。它由单排铝管组成，铝管上覆盖着薄层（4-8毫米）的金属泡沫。通过风洞测试，考虑了各种参数对热工液压性能的影响，包括雷诺数，管间距，泡沫高度和泡沫类型。结果表明，如果能够在泡沫和管之间实现良好的金属结合，则具有较小管间距，较小泡沫高度且由高比表面积泡沫制成的金属泡沫覆盖的管在更高的空气流速下可能具有强大的优势。 （> 4 m / s）与螺旋翅片管相比。粘结是通过导电环氧树脂胶完成的，发现对最终结果有很大影响，这表明强烈需要一种经济高效的钎焊工艺，以将金属泡沫连接到管子表面。
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