An experimental study was made to investigate heat transfer and air flow around the flat tubes of in-line flat tube banks with laminar forced convection. Measurements were conducted for sixteen tubes in the flow direction; four rows of four tubes, three air velocities (0.6, 0.8 and 1.0 m/s) and Reynolds numbers ReDh = 527, 703 and 880, where Dh is the hydraulic diameter of the tube. The total heat flux supplied in all the tubes was 968, 2259 and 3630 W/m2, respectively. The study results indicate that the average Nusselt number of all the flat tubes increased by 23.7%-36.7% with Reynolds numbers varying from 527 to 880 with fixed heat flux; also the average Nusselt number increased by 11.78%-23.75% at varying heat fluxes of 968, 2259 and 3630 W/m2, respectively at Reynolds number Re = 703. In addition, the pressure drop decreased with the increase of Reynolds number. The Nusselt number-Reynolds number correlation was found to be and the correlation yielded good predictions of the measured data with the mean error R2 = 99.2%.
展开▼
机译：进行了实验研究，以研究带有层流强制对流的直列扁平管束的扁平管周围的热传递和空气流动。在流动方向上对16个管子进行了测量。四排四管，三种风速（0.6、0.8和1.0 m / s），雷诺数ReDh = 527、703和880，其中Dh是管的水力直径。在所有管中提供的总热通量分别为968、2259和3630 W / m2。研究结果表明，在固定热通量的情况下，所有扁管的平均努塞尔数增加了23.7％-36.7％，雷诺数从527变化到880。在雷诺数Re = 703的情况下，在968、2259和3630 W / m2的不同热通量下，平均努塞尔数也分别增加了11.78％-23.75％。此外，随着雷诺数的增加，压降降低。发现Nusselt数-雷诺数相关性为，该相关性对测量数据具有良好的预测，平均误差R2 = 99.2％。
展开▼
