Optimization of Electron Beam Generated Inclined Conical Pin Fins For Efficient Heat Sinks

This study reports the results of a numerical investigation and optimization of the hydrodynamic and thermal performance of two new types of pin-fin and plate-fin heat sinks. The first type consists of inclined cones and is inspired by the larger heat transfer extents in impinging flow conditions, whilst the second type concerns wavy form plate-fins chosen such as to combine the effects of thermal boundary layer re-initialization, flow separation and large heat transfer area of classical plate fins. Fairly complex features are considered, which cannot be manufactured easily using traditional approaches. However, in this study we exploit the manufacturing flexibility offered by a new surface-structuring technology, which allows to produce more complex geometries than possible with the current state-of-the-art techniques. A simplified numerical methodology has been proposed to decrease the computational cost, which was then validated with respect to the literature and the laboratory tests. Baseline versions of the two proposed geometries were compared to more common geometries found in the literature in order to make a first choice. The results show that the inclined cone features can increase the heat transfer coefficient, especially in inverse configuration, whereas the wave structures require very large pressure losses to achieve similar levels of thermal performance. Subsequently, only inclined cones have been optimized using an Evolutionary Algorithm optimization platform. The optimized geometries increase the overall performance, especially reducing the pressure drop, in comparison to the geometries found in the literature.