An experimental study of air flow and heat transfer over in-line flat tube bank

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 directionfour 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 flu