Heat transfer study of 3 dimensional printed air-cooled heat sinks

Abstract

The study explores the heat transfer capabilities of novel heat sinks fabricated by Selective Laser Melting (SLM), an additive manufacturing technique, subjected to an air jet impingement. Four different heat sinks were fabricated from AlSi10Mg powder and they consists of a cylindrical design, and three axially perforated designs, viz., hollow, tapered and nozzle. The results show that the Nusselt numbers of the cylindrical heat sink are up to 6.8% higher on average as compared to other heat sinks. However, the heat transfer for each unit cell for the cylindrical heat sink was worse than the other heat sinks, with the tapered heat sink being the best, performing an average of 84.6% better than the cylindrical heat sink. This is due to the increased surface area caused by perforations and the minimizing of air separation within the fins. The cylindrical heat sink was also compared with conventional fabricated heat sinks. It was found that the 3D printed cylindrical heat sink performs at a higher Nusselt number than the others at lower Reynolds number because of lower thermal resistances, but performs worse than the others at higher values due to the enhanced fluid mixing in the porous heat sinks.