Optimization of Radial Fin Tubes Heat Exchanger with Minor Rectangular Annular Fins

Radial fin tubes heat exchanger (HE) is a tool applied to transfer heat generated from the energy dissipation of an electronic equipment or heat exchanger. Increased heat transfer in this tool continues to be developed using fin disturbance. Therefore, this study evaluated minor rectangular annular fins (MRAFs) as extended surfaces in radial fin tubes that have the potential to increase flow turbulence intensity and convective heat transfer coefficient. 3-D numerical analysis using Computational Fluids Dynamic (CFD) code Fluent is performed to obtain flow characteristics and heat transfer in HE radial fin tubes with MRAFs. The fin optimized parameters are the thickness and height of the MRAFs with constant ReD. While the optimal combination identification is determined is the highest heat transfer value of each variation. The results showed that by changing the dimensions of thickness and height MRFAs can increase the intensity of turbulent flow and convective heat transfer coefficient. However, the gap between fins with MRFAs shows the smaller Nusselt number. This is because the flow of freestream is hampered by secondary flow separation. The optimal combination is obtained on a 5 mm height variation with 1.5 mm thickness.