Natural Convection Heat Transfer from Fractal-Like Fins

The results of a computational investigation into the performance of fractal-like fins under conditions where natural convection is the sole heat transfer mechanism are presented. Fractal patterns such as the Sierpinski carpet have previously been shown to increase surface area significantly, compared to classical geometries, while also reducing mass. This study examines fin performance for a baseline case (a square fin) relative to the first four fractal iterations of fins inspired by the Sierpinski carpet fractal pattern. To evaluate thermal performance, constant heat flux conditions were applied to the base of the fins. Geometric fin parameters, surface heat flux, fin scale, and fin orientation were varied to understand their role with regard to fin effectiveness and fin efficiency. Fin effectiveness was found to be greatly increased through the use of fractal-like fins, due to the increase in surface area per fin volume. Fin effectiveness per unit mass was also found to be improved significantly, which could lead to use in applications where the fin mass is a selection criterion.