Abstract The heat transfer and flow characteristics of the air-water cross flow over cambered ducts were experimental and numerical investigated. The sequence of their Core Volume Goodness Factor (CVGF) is cosinoidal, parabolic, circular, trapezoidal and rectangular ducts successively from superior to inferior. Cambered ducts have more uniform temperature difference distribution than the equal cross section duct, and it has the minimum temperature difference in inlet and outlet of the cosinoidal duct. With the optimal overall heat transfer performance, the cosinoidal duct is superior to that of the rectangular duct by 7.3%–28.1%. In the cosinoidal duct, the smaller the amplitude is, the better the heat transfer performance is. The thickness of the thermal and velocity boundary layers adjacent to the wall surface decreases constantly with increased Reynolds number. In the near wall region, n = 5um, the main heat transfer area is the peak and middle areas, but with weaker heat transfer performance in the trough region. Although gradually expanding cambered duct slows down the flow velocity, the structure form decreases the pressure drop loss during the flow process. While improving the convective heat exchange capability of the upstream, the heat transfer area of the downstream is also improved to boost the overall heat transfer performance.

中文翻译：

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典型弧形管道传热和流动特性分析

摘要 对弧形管道上空气-水交叉流的传热和流动特性进行了实验和数值研究。它们的核心体积良度因子 (CVGF) 的顺序是余弦、抛物线、圆形、梯形和矩形管道，从上到下依次是。弧形风管比等截面风管温差分布更均匀，余弦风管进出口温差最小。在整体传热性能最优的情况下，余弦风管优于矩形风管7.3%~28.1%。在余弦管中，振幅越小，传热性能越好。与壁面相邻的热边界层和速度边界层的厚度随着雷诺数的增加而不断减小。在近壁区，n = 5um，主要传热区域是波峰和中部，而波谷区的传热性能较弱。虽然逐渐扩大的弧形管道减缓了流速，但这种结构形式减少了流动过程中的压降损失。在提高上游对流换热能力的同时，也提高下游传热面积，提升整体传热性能。虽然逐渐扩大的弧形管道减缓了流速，但这种结构形式减少了流动过程中的压降损失。在提高上游对流换热能力的同时，也提高下游传热面积，提升整体传热性能。虽然逐渐扩大的弧形管道减缓了流速，但这种结构形式减少了流动过程中的压降损失。在提高上游对流换热能力的同时，也提高下游传热面积，提升整体传热性能。