Effect of edge region on heat transfer and pressure drop performances of small plain plate-finned tube bundles

In the present paper, the heat transfer and pressure drop characteristics of small plain plate-finned tube bundles with 4 tube rows in staggered arrangement are numerically studied. The focus is paid on the effect of edge region. The results indicate that tube arrangement of 6/6/6/6 is better than that of 6/5/6/5. The effect of edge region cannot be neglected when the tube number is small. The friction factor of real model is 13%~14% smaller and the Nusselt number is 15%~18% smaller than that of the simplified symmetrical model as reference. It is recommended to use the proposed formulas to estimate the Nusselt number and friction factor of the small plain plate-finned tube bundles.