Hydro-thermal performance of an I-shaped pin fin microchannel heat sink with variable pin fin height, thickness and orientation

Novel I-shaped pin fins have been investigated numerically to enhance the hydro-thermal performance of a microchannel heat sink. The proposed I-shaped design reduces the obstruction to the flowing fluid and enhances the heat transfer surface area. The height and thickness of pin fins are varied in the range of 0.75–2 mm and 0.1–0.4 mm, respectively. Water acts as coolant while Copper is the material of the heat sink. Base temperature, Nusselt number, pressure drop and thermal performance factor are the key performance parameters. Results indicate that the base temperature decreases and pressure drop increases as the fin height and thickness are increased. The optimum fin geometry is identified as the one with a height of 1.5 mm and thickness of 0.4 mm, yielding a thermal performance factor of 1.16. To explore the effects of the angular orientation of fins, four distinct designs of heat sinks are created. The fins in each design are varied in the range 15°-90°. The highest thermal performance factor of 1.29 is achieved at 15°orientation, depicting a performance enhancement of 29 % as compared to the square fin base case. Angular-oriented fins create converging-diverging channels. These give rise to distinct velocity profiles which dictate the hydro-thermal performance.