Immersed jet impingement heat transfer for servers in immersion cooling data center: A parametric study

Immersion and jet impingement cooling are effective solutions for addressing the thermal dissipation challenges of high-power electronic components in data centers. For the improvement of the thermal performance of hotspots in immersion cooling servers, a jet-assisted immersion cooling is presented and studied. A numerical investigation considering the geometry of the heat sink, jet impingement height, mainstream flow rate, jet flow rate, and the distribution of jet orifices was carried out to unveil the convective heat transfer and flow field in immersed jet impingement cooling. The findings suggest that intermittent fins outperform continuous fins regarding thermal performance and flow resistance due to the unobstructed outflow, with the optimal jet heights being 2 mm and 2.5 mm. Throughout studied parameter ranges, larger mainstream and jet flow rates enhance thermal performance, albeit with a significant increase in pumping power consumption. The configuration of the jet orifices significantly improved temperature uniformity and saved pumping power consumption. Under the primary and jet flow rates of 1.31 L/min and 6.78 L/min, respectively. Specifically, under the mainstream and jet flow rates of 1.31 L/min and 6.78 L/min, respectively, the temperature difference on the heat source surface is reduced by 38.74%, and the pumping power is lowered by 7.81% when using Orifice Plate 2 versus the original uniformly distributed Orifice Plate 1. However, for elevated jet flow rates or longer liquid flow pipes, the internal pressure loss during the jet impingement has limited impact on the total pumping power. The present work provides a basic understanding of the immersed jet impingement cooling with cooling oils and serves as the guidance for addressing the local hotspot in immersion cooling servers with limited pumping power consumption.