Thermal performance improvement based on the hybrid design of a heat sink

There are many scientific attempts to improve the thermal performance of heat sinks that used to remove heat from energy sources using the merge between two types of fins. Here, vertical merging based to convert part of the original size (longitudinal fin) into pin fins was adopted. This lead to the emergence of a hybrid design with imposing the total weight is constant. Therefore, the full size of the original model stabilized for all presented models to achieve both of the usability in limited space and determine the best performance from adopting models. The heat transferred, thermal resistance, Nusselt number and convection heat transfer coefficient were analytically calculated under natural convection and range of Ra number (10(5), 10(6) and 10(7)). All these considerations were applied to the variable surface area by (1-1.8) times. In this study, two validations way considered; Numerical solution (ANSYS simulation) and data adapted from other references. Results show the excellent reliability of the analytic model based on a high level of agreement by (0.52%-1.2%). The results showed; heat transferred, thermal resistance and Nusselt number enhanced by (78%-87%), (42%-47%) and (79%-82%), respectively. In particular, all parameters have significantly improved an area ratio of less or equal than 1.5. On the other hand, Mutually overcoming between the effects of heat transferred and surface area on the thermal performance lead to a discrepancy in the behavior of convection coefficients. Therefore, Stability of performance can occur in an area ratio higher than 1.5. Meanwhile, the increment of enhancement of heat transferred ratio and thermal resistance ratio decreases with large Ra. Because of the weakness in thermal performance at the original model that associated with a small Ra number. (c) 2019 Karabuk University. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).