Freeform-Optimized Shapes for Natural-Convection Cooling

This paper presents numerical and experimental results for natural-convection cooling of freeform-optimized shapes. State-of-the-art 3D-printing technologies are utilized to fabricate innovative heat sink designs. Biomimicry was used to develop heat sink shapes based on brain coral. CFD-optimized designs were systematically analysed altering the number and size of air inlet holes to improve airflow circulation. Selectively laser-sintered polyamide heat sinks were used for experimental airflow testing, whereas selectively laser-melted aluminium heat sinks were used for thermal performance testing. Material properties as well as heat sink thermal resistances were determined. A good agreement between numerical and experimental results was found. The validated numerical approach can be used to further enhance freeform heat sink shapes. Moreover, the non-uniform material properties, which 3D-printed parts inherently feature, that were experimentally determined as part of this study can be included into the numerical model and optimization strategies.