Enhancement of Confined Air Jet Impingement Heat Transfer Using Perforated Pin-Fin Heat Sinks

Abstract

The development of semiconductor fabrication process and electronic packaging technology causes the size and weight of electronic components to decrease consistently. Along with the increasing operating power, the heat generation rate of the electronic products apparently gets higher. For the sustainable future, we must limit using natural resources and also reduce the greenhouse gas emission. Efficient removal of heat from the electronic products in a limited space becomes a major task in electronics cooling. Air impingement cooling with a heat sink is an attractive option for electronic cooling, because it is inexpensive, robust, and localized. Rapid heat transfer from heated surfaces and reducing material weight is also becoming a major task for the design of heat exchanger equipment for electronic cooling. Rectangular plate fins as extended surfaces are good heat transfer equipment which are widely used for various industrial applications. Heat transfer rate can be improved by introducing perforations, porosity, or slots. Moreover, due to restrictions in setup space and economic reasons, heat transfer equipment has been required to be much more compact in size and lighter in weight. Studies on three-dimensional plate and pin-fin heat sinks are extensive. But no focus has been yet given on air jet impingement heat transfer with perforated pin-fin heat sink. Thermal-fluid characteristics of solid and perforated pin-fin heat sinks cooled by confined air jet impingement are investigated numerically in this study. The SST k-ω turbulence model is used to predict the turbulence flow parameters. The numerical model is verified with previously published experimental data. Flow and heat transfer characteristics are presented for the impinging Reynolds number, Re = 5000−25000 having constant impingement distance (Y/D = 8), fin width (W/L = 0.1), and height (H/L = 0.5). The main objective of this study is to examine the effects of fin perforations on the thermal performance of pin-fin heat sinks. Results show that thermal resistance decreases and fin efficiency increases with the increase of Reynolds number due to perforation. Thus, this kind of heat sink equipment would reduce the cooling power consumption rate.