八边形翼攻角对翅片管空气侧流动与换热特性的影响

在传统翅片管上加装八边形翼涡发生器以强化传热。利用FLUENT软件对八边形翼翅片管模型进行了数值模拟,研究了不同雷诺数(Re)下八边形翼攻角(10°,20°,30°,40°)对翅片管空气侧流动与换热特性的影响。结果表明,八边形翼攻角对管后尾迹区换热影响显著;与平直翅片管相比,加装八边形翼的翅片管空气侧在不同攻角、Re下的平均努塞尔数(Nu)提高了13.1%~43.1%,相应的阻力系数(f)增加了6.9%~61.1%;通过对综合传热性能评价因子(PEC)的分析发现,在Re为862~3 735时,八边形翼攻角为20°的翅片管综合传热性能最佳。

Air-side Flow and Heat Transfer Characteristics of Fin-tube with Octagonal Winglet at Different Attack Angles

Octagonal winglet vortex generators are installed on the traditional finned tubes to enhance heat transfer.The numerical simulation of the finned tube model with octagonal winglet is carried out by using FLUENT software,and the effect of the attack angles (10°,20°,30°,40°) of the octagonal winglet on the air-side flow and heat transfer of the finned tubes is studied at different Reynolds numbers(Re).The results show that the attack angle of the octagonal winglet has a significant effect on the heat transfer in the wake area behind the tube.Compared with the flat finned tube,the average Nusselt number (Nu) of the air side of the finned tube with octagonal winglet is increased by 13.1%~43.1% at different attack angles and Reynolds numbers,and the corresponding resistance coefficient (f) is increased by 6.9%~61.1%.By analysizing the PEC factor,the finned tube with the attack angle of 20° for the octagonal winglet has the best comprehensive heat transfer performance in the range of Reynolds number 862 to 3 735.