Jin-Sheng Leu
Depart, of Mech. Engi., Far East College, Tainan, Taiwan 744
Jiin-Yuh Jang
Department of Mechanical Engineering, National Cheng-Kung University, Tainan, Taiwan
Shin-Li Chen
Department of Mechanical Engineering, National Cheng-Kung University, Tainan, Taiwan 70101
Cheng-Hui Tu
Depart, of Mech. Engi., National Cheng-Kung University, Tainan, Taiwan , 70101
Experiments were carried out to study the thermal-hydraulic characteristics for rectangular finned-tube heat exchangers with elliptic tube having axis ratio of 2.83:1. Four rectangular finned tubes with fin height 7 mm and 10 mm and with staggered and in-lined arrangements have been investigated for different values of inlet frontal velocity ranging from 1 to 6 m/s. The results were compared with the corresponding elliptic finned-tubes with the same axis ratio 2.83 and fin height 7 mm. It is shown that rectangular finned-tube heat exchangers have lower heat transfer performance and larger pressure drops than elliptic finned-tube heat exchangers. In addition, a two−dimensional fin efficiency analysis for the rectangular and elliptic fins with elliptic tube was presented for a wide range of Biot numbers. The results indicated that the fin efficiency for rectangular fin is lower than that of elliptic fin.