面向金属泡沫散热器设计的自然对流拓扑优化

To overcome the challenges ol low heat dissipation efficiency in traditional block-type metal foam heat sinks and their inability to meet the cooling requirements of high-power electronic devices, a three-dimensional topology optimization method based on the lattice Boltzmann and level set methods is developed. Firstly, the lattice Boltzmann method is employed to simulate the flow and heat transfer processes within the porous medium. Then, the adjoint lattice Boltzmann method is used to calculate the gradients. Finally, the level set function is updated based on the reaction-diffusion equation. By conducting topology optimization of the natural convection process in a square cavity with heat-generating elements at the bottom, four optimized heat sink structures with characteristic Grashof numbers ranging from 2. 4 X 102 to 1. 2 X 10' are obtained. The enhanced heat transfer performance of the heat sinks is quantitatively evaluated, and the underlying mechanisms are analyzed. The research findings indicate that as the Grashof number increases, the dominant heat transfer mechanism shifts from conduction to convection. The optimized structures transform from extended branching patterns to compact flower-like structures, creating additional space for the development of more flow vortices. Compared with traditional block-shaped metal foam structures and slotted metal foam block structures, the proposed optimized structures demonstrate superior heat dissipation performance. The branch structures and hollow structures optimize the flow within the cavity, resulting in an improvement in heat dissipation efficiency of over 29. 7%. These results highlight the effectiveness of the proposed topology optimization method and provide theoretical guidance for the design of novel metal foam heat sinks.