Pore-scale numerical investigation on comprehensive heat transfer performance of homogeneous and graded metal foam heat sinks

In order to improve the heat dissipation efficiency of heat sinks, heat sinks filled with metal foam were proposed and numerically studied in this work. Different shapes, including the tetrakaidecahedron, triangular prism, and equivalent tetrahedron, were employed to develop geometries for the cells, ligaments, and nodes of the metal foam. Computational simulation was carried out to analyze the hydraulic and thermal performance of the homogeneous metal foam(HMF)-filled heat sinks and graded metal foam (GMF)-filled heat sinks. The study found that well-designed GMF-filled heat sinks can improve both hydraulic and thermal performance. A graded pores per inch (PPI) negative change along the X-axis direction can improve the comprehensive heat transfer performance (CHTP), and the positive change has a similar effect. Graded PPI negative change along the Y-axis direction can effectively improve the CHTP, while the positive change has no effect. Moreover, a greater thickness of the metal foam with a larger PPI leads to better performance. GMF-filled heat sinks can also effectively reduce the surface temperature of the bottom plane and enhance the convection performance.