Heat transfer, pressure drop, and fluid flow patterns in yawed tube banks

Complementary heat transfer, pressure distribution, and flow visualization experiments were performed to investigate the effect of yaw on both staggered and in-line tube tanks. The heat transfer measurements were carried out on a row-by-row basis, and pressures were measured internal to the tube banks as well as upstream and downstream. Air was the heat transfer fluid. The visualization experiments revealed that yaw markedly affected the manner in which the flow impinged on the tubes of the in-line array, with a lesser effect of yaw on the flow field in the staggered array. At a given freestream Reynolds number, the Nusselt number generally decreased as the angle of yaw increased. The yaw effect was well correlated for the staggered array, but not so well for the in-line array because of the aforementioned flow field modifications. The in-line-array Nusselt numbers generally exceeded those for the staggered array, a trend which was accentuated at larger yaw. The pressure drop decreased with increasing yaw. In the present operating range, the in-line-array pressure drops were smaller than the corresponding staggered-array values.