Integrated-scale prediction of radiative properties of open-cell metal foam based on the pore-scale transfer and microscopic morphology of ligaments

In this work, with all the characteristic morphologies considered, a numerical method for achieving the prediction of radiative properties of open-cell metal foam integrating different scales is presented. For the modeled micro-scaled rough ligament surface, the FDTD method is adopted for predicting the radiative properties of ligament surface elements. Meanwhile, at macro scale, the metal foam sheet is reconstructed by the CT technique, and the radiative properties of reconstructed foam sheet are numerically calculated with the Monte Carlo method. In the procedure of applying the introduced method, the radiative parameters of ligament surface elements, including the directional-hemispherical reflectivity and specularity parameter, are extracted from radiative properties of ligament surfaces. Then, these radiative properties are used for achieving the further numerical prediction of radiative behaviors of metal foams. The integrated-scale prediction of radiative properties of open-cell metal foam is accomplished by the introduced method, which integrates microscopic morphology of ligament surface and macroscopic solid ligament network. Furthermore, the presented method is applied for calculating the spectral radiative properties of nickel foams. The presented method is proven to be valid by comparing with experimental results. Additionally, the effects on the radiative properties caused by incident wavelength and angle are discussed.