A Numerical Study on Fluid Flow and Heat Transfer Characteristics for External Longitudinal Finned Tube

In this paper, a modified k-omega model and the wall function approach was applied to numerically simulate fully developed fluid flow and heat transfer in a shell-and-tube heat exchanger with longitudinal finned tubes. The numerical model used the distributed resistance method along with the concept of volumetric porosities, anisotropic surface permeabilities to account for the presence of tubes in the heat exchangers. The computed results obtained, which are compared with the shell-and-tube heat exchanger where bare tubes were used, lead to the conclusion that higher heat transfer rates can be achieved using external longitudinal finned tubes at the expense of a reasonable pressure drop. Further studies on the fluid flows, temperature rises and quantity of heat transfer at different Reynolds numbers are conducted and the mechanisms involved are explored.