Improving the natural convection of the heat sink inside an enclosure by fin perforation for electronic applications

The present study aims to enhance the natural convection in the heat sink inside an enclosure by perforating fins for power electronic applications. The enclosure is a cube that is manufactured in such a way that the upper and lower surfaces, as well as the front and back surfaces, are thermally insulated. The right surface is hot, while the left surface is cold at a temperature difference ∆T of (4°C, 8°C, 10°C). The heat sink used consists of five fins that are attached to the heated surface. The heat sink fins are perforated with perforation number NP (4, 8, 12, and 16) and perforation diameter DP (0.5 and 1 cm). Temperatures are measured using 13 thermocouples placed within the enclosure and the temperature distribution is determined using a FLIR E30BX IR thermal camera, while velocity contours are obtained using numerical software. The main results showed improvement in heat transfer with an increase in the number of perforations and (DP = 1 cm) was found to be more efficient than (DP =.5 cm), for instance, when (∆T = 10°C) for (NP = 16) and (DP =.5 cm). There is a 2.9% improvement in temperature reduction on the fins' tip, while at =(DP = 1 cm), the percentage of improvement was 3.5% and showed a greater expansion of the velocity lines between the fins at (∆T = 10°C), where the rate of increase in the velocity contours from (∆T = 4 and 8°C) reaches 20% and 7% respectively. In addition, heat sinks with perforated fins are both lighter and more cost-effective in terms of metal usage during the manufacturing process.