Enhancement of Natural Convection Heat Transfer of Hybrid Design Heat Sink

Each type of fin has been investigated separately in many researches that are concerned with finding its performance under varying operating conditions, enhancement of heat sink performance by using the combination between two types of fin was investigated in this study. To establish a scientific comparison between models, a constant weight of the heat sink has been imposed. For that the total size of the original model (longitudinal-fin) was stabilized. Converting part of the original size into spin fins led to the emergence of a hybrid design that was studied by analytical and computational simulation. Under natural convection and Ra=10(7), calculation process was performed for varying the surface area between (1-1.8) times. The strong agreement of the validation results (0.31 %-0.52 %) showed the reliability of the analytical model based on the ANSYS simulation. Hence, the results demonstrated that the hybrid designs have a discrimination in several aspects; reducing the fin temperatures is about (2.7% to 8.8%), lower thermal resistance by (24% to 46%) and augmentation of heat transferred by (31%-80%), compared with original heat sink. Improvement of thermal resistance and heat transferred does not behave in the same approach with all models (area ratio of greater than 1.6), because of the overlap between the negative effect of convection coefficient and increase of surface area. So, the approximate steady state can be happened.