Effect of strut microstructure on multiscale radiation properties of porous foams

Porous materials, widely used in engineering due to their excellent physical properties, have significant engineering and academic research value in their mechanism of radiation heat transfer. Micro-cellular foams are composed of a large number of struts and walls with micro-scale radiation effect, making it difficult to analyze the influence of strut micro-structure on radiation properties. In this study, the radiation parameters of the curved triangular prism-shaped struts are calculated using the finite element electromagnetic method, and the influence of the strut micro-structure parameters and the macroscopic parameters of the foam on the radiation characteristics is analyzed. The results demonstrate that the radiation properties of the equal-volume cylinder model, compared to the double-layer cylinder model, are closer to those of the curved triangular prism struts. The incidence angle has a negligible impact on the radiation parameter deviation of the struts. It is difficult to ignore the radiation parameter deviation of concave-curved triangular prism-shaped struts. The macroscale radiation properties of the foam are significantly influenced by the microscale radiation properties of the struts in the situation of low porosity, large pore size, and high strut volume ratio.