The effect of cell aspect ratio on flow and heat transfer characteristics of anisotropic Kelvin foam

High-porosity foam materials are widely used in aircraft thermal management systems due to their light weight and large surface area. The optimization of the geometric parameters in pore scale is crucial for effectively improving the overall heat transfer performance and reducing the structural weight. This paper focuses on anisotropic Kelvin foam structures and uses a hybrid lattice Boltzmann method and multi-GPU acceleration technology to perform conjugate heat transfer numerical simulations that considers both foam skeleton conduction and forced convection heat transfer in the pores on the pore scale. Different cell aspect ratios (H/D = 0.5, 0.75, 1.0, 1.5, 2.0) were selected with various Reynolds numbers (Re = 10, 100, 1000) to study the effect of cell aspect ratio on flow and heat transfer characteristics. The results show that under different Re conditions, as the H/D of the anisotropic Kelvin foam decreases, the flow resistance and Nusselt number inside the foam increase. As the Reynolds number increases, the effect of convective heat transfer becomes stronger, and the influence of H/D becomes more significant. In addition, compared with flow resistance, the structural heat transfer performance changes more rapidly with H/D, and therefore, the comprehensive heat transfer factor is inversely proportional to H/D, which means reducing the H/D of Kelvin foams can effectively improve the overall heat transfer performance of foam structure.