Experimental study of partially metal foam wrapped tube bundles

Abstract

Overall heat transfer and pressure drop for three novel staggered tube banks with tubes partially wrapped with metal foam layers have been experimentally studied in an open circuit wind tunnel. The positions of the metal foam layers around the tubes are different in the studied tube banks, TB1, TB2, and TB3. In other words, the angles between inlet flow direction and metal foam layers placement around the tubes are 0, ±45, and ±90° in TB1, TB2, and TB3, respectively. The most interesting result of the present study is that heat transfer and pressure drop are closely related to the position of the porous layers around the tubes and the thermal performance augmentation could be achieved by selecting suitable positions for metal foam layers. The results indicate that the tube bank in which metal foam layers are centered at 0 and 180° from the front stagnation point of tubes (TB1) exhibits a better heat transfer performance at the same pressure drop comparing with TB2 and TB3. To illustrate this, at about 7 Pa, TB1 disposes of 62% and 82% more heat than TB2 and TB3, respectively.