Effect of Knurled Fin Surface on Thermal Performance of Perforated Fin Heat Sink

摘要

Fabricating perforations in fins causes improvement in heat dissipation rate with lower pressure drag up to a specific perforation number and size of perforation. Again knurled surfaces augment heat transfer rate due to turbulence promotion as well as substantial increase in surface area. The present work investigates thermal performance of heat sink using perforated pin fins with different knurled surfaces. Three-dimensional computational fluid dynamics simulations have been performed to explore the effects of various different knurling geometries on fin surface, perforation number, and size on system performance. A multicriteria decision-making optimization method such as Multi-Objective Optimization under Ratio Analysis (MOORA) has been applied to select the best heat sink configuration. It has been observed that the rate of heat transfer for perforated fins up to a particular perforated area is always greater than the solid fins, and with the variation in knurling geometry on fin surface, heat dissipation rate enhances significantly. Conversely, pressure drop around heat sink decreases with the increment of number and size of perforations. However, due to knurling on fin surface, pressure drop increases. Finally, exergy analysis has also been carried out to calculate second law efficiencies of circular perforated fins using different knurling patterns with increasing number of knurling teeth.