Study on bionic leaf-vein like heat sinks topology optimisation method

Finned heat sinks are high-efficiency heat dissipation equipment, widely used in various industrial and civil fields. In the nuclear field, many systems use finned heat sinks to enhance heat dissipation, such as spent fuel pools, passive decay heat removal systems, and reactor cavity cooling systems (RCCS). To improve the heat dissipation capacity of heat sinks, this study proposes a novel bionic leaf-vein-like heat sink topology optimisation method (bionic topology optimisation method). This method consists of two steps: bionic optimisation and topology optimisation. In this study, a bionic optimisation method was used to design leaf-vein bionic heat sinks (ordinary bionic heat sinks). Compared to the traditional plate-fin heat sink, the ordinary bionic heat sink reduced the thermal resistance and volume by 6.45 % and 22.50 %, respectively. Furthermore, the convective heat transfer coefficient was calculated by identifying the solid-air boundary elements. Subsequently, based on the natural convection surrogate model, topology optimisation was performed on an ordinary bionic leaf-vein heat sink under RCCS engineering conditions. Further numerical simulation analysis showed that the unique leaf-vein-like fin structure obtained by topology optimisation not only enhanced heat conduction, but also increased the airflow velocity near the fins and disrupted the airflow. Therefore, cooler air could enter the flow channels more easily. Under the combined effects of the airflow velocity and heat transfer temperature difference, the heat dissipation capability of the topology bionic heat sink was significantly improved. Compared to the ordinary bionic heat sink, the thermal resistance of the topology bionic heat sink was reduced by 36.40 %.