Numerical Investigation to the Effect of Perforations Geometry and Position on Thermal Performance of Flat Plate Heat Sink

A multi-dimensional computational fluid dynamics modeling was conducted on a flat plate heat sink equipped with four perforated fins. The numerical investigation was performed under conduction heat transfer for the heat sink body and natural convection heat transfer for the enclosure. The combined effect of fin’s perforations' shapes (circular, square, triangular) and their positions (bottom, middle, top) on thermal performance were investigated. The heat sink with solid fins was used as a reference line for thermal performance comparison and experimental validation. The results showed that the fins’ temperature differences (ΔT) between the bottom and top regions of used fins were increased when heat sink fins were perforated. The minimum ΔT was noticed when the circular perforation was used regardless of the matrix position whereas the maximum ΔT was recorded when the triangular perforation shape was used. Besides, the value of ΔT was increased when all perforation matrices were moved from the top to the bottom of the fins. Whereas, the heat transfer coefficient was greater when the heat sink was equipped with perforated fins but the effect of perforations’ shapes and positions were not that significant. In conclusion, the temperature distribution and heat dissipation rate were the best when the heat sink was equipped with circular perforation fins. The attained numerical results were validated by comparing them with experimental results conducted for this study. The buoyancy effect inside the enclosure and at the vicinity of the fins was increased when the HS fins were circularly perforated and top positioned. The value of ΔT was increased by 15.6% but the heat transfer coefficient was also increased by 29.6%. Consequently, the thermal performance represented by the heat dissipation rate to the surrounding was improved. This gives the optimum thermal performance to the circularly perforated fins at most of the tested conditions.