Experimental Investigation of the Effect of Extended Surfaces on the Performance of Tube Banks in Cross Flow

Abstract

Experimental results of the heat transfer and pressure drop of an air flow across different configurations of extended surfaces of in-line and staggered tube bank arrangements are reported.Empirical equations relating the heat transfer, pressure drop and flow velocity are obtained. Results indicate that extended surfaces may enhance the heat transfer, but at the same time, they will increase the pressure drop.It is concluded that for Reynolds number (Re) ≤ 6 × 103, the simple basic configuration of a circular cylinder in the in-line arrangement is recommended since it has the highest ratio of heat transfer to pressure drop (Nu/ΔP*). For Re > 6 × 103, the configuration with the extended surface in the downstream end (straight fin) of a staggered arrangement is recommended.