Experimental and numerical analysis of heat transfer and flow characteristic in parabolic ducts
Experimental and numerical analysis of heat transfer and flow characteristic in parabolic ducts
复制标题
抛物线管道传热和流动特性的实验和数值分析
DOI：
10.1016/j.ijheatmasstransfer.2019.118912
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发表时间：
2020
影响因子：
5.2
通讯作者：
Hongbo Zhang
中科院分区：
文献类型：
--
作者：
Xilong Zhang;Bilong Liu;Jiang Liu;Xingang Wang;Hongbo Zhang
本文对不同焦距（P= 120 mm、140 mm和160 mm）的抛物面通道的传热和流动特性进行了分析，并分别与矩形和梯形通道进行了比较。建立了弯管内的控制方程，包括质量守恒方程、动量方程和能量守恒方程。结果表明，三种通道的整体传热性能从好到差的顺序为抛物线形通道、梯形通道和矩形通道。抛物线形通道的强化传热效果最好，比梯形通道和矩形通道分别提高了5.1%和25.4%。这意味着，虽然发散型结构降低了流速，从而减弱了管内对流换热的强度，但它提高了下游换热面积，降低了流动过程中的压降损失，从而促进了整体换热性能的提高。另外，抛物面流道内的温差分布最均匀，是改善和强化传热性能的重要因素。从场协同理论的角度来看，平均场协同角随焦距的增大而变小，场协同变好。
In this paper, the heat transfer and flow characteristics of parabolic ducts with different focal lengths (P= 120 mm, 140 mm, and 160 mm) are analyzed and compared with rectangular and trapezoidal ducts respectively. The governing equations in the curved ducts, including the mass conservation equation, momentum equation and energy conservation equation, are established. The results show that the order of the overall heat transfer performance of the three ducts from the best to worst is parabolic duct, trapezoidal duct and rectangular duct. The parabolic duct has the best overall enhanced heat transfer performance, which is 5.1% and 25.4% larger than that of the trapezoidal and the rectangular ducts respectively. This means that, although the divergent type structure reduces the flow velocity and thus weakens the intensity of convective heat transfer in the duct, it improves the downstream heat transfer area and reduces the pressure drop loss in the flow process, thus promoting the improvement of overall heat transfer performance. Besides, the temperature difference in the parabolic flow duct has the most uniform distribution, which is an important factor to improve and strengthen heat transfer performance. From the perspective of field synergy theory, the average field synergy angle decreases with the increase of focal length, and the field synergy becomes better.