Forced Convective Heat Transfer Enhancement with Perforated Pin Fins Subject to an Impinging Flow

Foo, J.J., Pui, S.Y., Lai, Y.L. and Chin, S.B. , SEGi Review 5(1), 34-45, 2012

The rapid growth in high speed multi-functional miniaturized electronics demands more stringent thermal management. The present work numerically investigates the use of staggered perforated pin fins to enhance the rate of heat transfer while subject to a vertical impinging flow. In particular, the number of horizontal perforations and the vertical and horizontal diameters of perforation on each pin are studied. Results show that the Nusselt number of pins with horizontal and vertical perforations is about 9% higher than that for the solid pins and it increases with the number of horizontal perforations. Pressure drop with perforated pins is reduced by about 10% compared with that in solid pins. Perforation produces smaller but larger number of vortices downstream of the pins which increases convective heat transfer but reduces pressure losses. However, further increasing the perforation diameters leads to a significant drop in thermal dissipation. Overall, pin fins with vertical and horizontal perforations are preferred for heat sink facing an oncoming vertical flow.