Abstract The flow characteristics and heat transfer performances of tube with ellipsoidal dimples are numerically investigated in this present work. Skewness and kurtosis of dimpled tube wall surface are calculated by discrete method. Effects of dimple cross section shape, number, cross distribution angle and pitch on thermal-hydraulic performance and roughness parameters are discussed. These results show that compared with the smooth tube, the dimpled tube has a better thermal-hydraulic performance due to the flow mixing and flow separation are significant increase. In addition, the influence law of dimple cross section shape, number and pitch on skewness, kurtosis and thermal-hydraulic performance is the larger skewness and smaller kurtosis, the better thermal-hydraulic performance. However, it is unable to evaluate the effect of dimple cross distribution angle on thermal-hydraulic by using skewness and kurtosis.

中文翻译：

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从偏度和峰度角度评价波纹管的热工水力性能

摘要 本文对椭圆形凹坑管的流动特性和传热性能进行了数值研究。波纹管壁面的偏度和峰度采用离散方法计算。讨论了凹坑截面形状、数量、交叉分布角和节距对热工水力性能和粗糙度参数的影响。这些结果表明，与光滑管相比，由于流动混合和流动分离显着增加，凹陷管具有更好的热工水力性能。此外，凹坑截面形状、数量和节距对偏度、峰度和热工水力性能的影响规律是，偏度越大，峰度越小，热工水力性能越好。然而，