Experimental Performance of Novel Foam and Schwarz Surface Heat Sinks

In this experimental investigation two novel heat sink designs that employ different flow phenomena for enhanced heat transfer are presented. Thermal and hydrodynamic performance comparisons are made for three foam heat sinks with and without fins and two heat sinks with zero-mean curvature based on the Schwarz minimal surface design. Results for a longitudinally-finned heat sink are presented as a baseline comparison against the complex foam and Schwarz “3D” heat sink designs. The heat sinks are manufactured using an investment casting process providing a means of fabricating complex designs as one monolithic piece with high thermal conductivity that would not be possible using traditional techniques. It is demonstrated that against pumping power and velocity parameters the foam structures perform reasonably well in the higher velocity range. It is shown that the pressure drop across the foam and Schwarz structures is significant and the application of these designs in real systems will depend on the design constraints of the system, e.g. the foams may work well in a fan mounted heat sink assembly but not in a typical telecommunications application where flow bypass is important.