Natural convection heat transfer in a three-dimensional enclosure under the effect of heated pin-fins of various shapes

Natural convection enhancement for heat sinks with the help of pin-fins has been extensively researched, but further investigations are still required regarding the technological development. In order to understand the effect of different pin-fins shapes on the heat transfer and fluid flow pattern in a three-dimensional air-filled enclosure, a numerical investigation is conducted. The enclosure is heated by the left wall, on which pin-fins are attached, and cooled by the right wall, while the other walls are considered adiabatic. A validation has been made with both experimental and numerical results from the literature, and a good agreement has been observed. Five pin-fins shapes with the same base surface area and length are tested: circular, triangular, square, pentagonal, and hexagonal. The findings show that the circular pin-fins exhibit the highest thermal performance. Furthermore, for different Rayleigh numbers, increasing the number of pin-fins improves the thermal performance of heat sinks.