基于偏态和峰度的丁胞传热管性能分析

建立含不同参数的正六边形截面丁胞传热管有限元分析模型，仿真研究雷诺数为5000~40000时丁胞组合类型、深度和直径对传热管中流体流动及传热性能的影响。此外，采用离散方法计算并分析丁胞参数对传热管表面偏态和峰度的影响。最终基于丁胞参数对偏态和峰度的影响规律对丁胞传热管的性能进行分析。研究结果表明，凹坑或凸起丁胞通过增强流体的回流效果及削弱流体边界层厚度，能够有效增强传热管内流体的流动及传热性能，且凹坑丁胞的影响优于凸起丁胞。此外，不同丁胞组合类型的影响表现为偏态越小、传热管的流动及传热综合性能越好。然而，对于凹坑丁胞传热管，其表面偏态越大、峰度越小，传热管的流动及传热综合性能越好，增加凹坑丁胞深度和直径可增大偏态、减小峰度。

Performance analysis of dimpled tube based on skewness and kurtosis

In this work, the numerical simulation model of the hexagonal tube with different parameter dimples has been established considering thermal-hydraulic performance. The effect of dimple types, dimple depth, and dimple diameter on the flow field characteristics, and heat transfer characteristics of dimple tubes were discussed under Reynolds numbers between 5000 and 40000. Skewness and kurtosis of dimpled tube wall surface were calculated by discrete method, and then the thermal-hydraulic performance of dimpled tube was analyzed based on the influence of dimple parameters on skewness and kurtosis. The results showed that the dimpled tube had a better thermal-hydraulic performance due to the recirculation flows and flow separation was a significant increase, and the effect of pit dimple was better than that of bulge dimple. In addition, the influence of different dimple types was that the less the skewness, the better the thermal-hydraulic performance of the heat transfer tube. However, for the pit dimple tube, the larger skewness and the smaller the kurtosis was, the better comprehensive performance of the thermal-hydraulic got. With the increase of the pit dimple depth and diameter, the skewness gradually increased, while the kurtosis value gradually decreased.