Numerical Investigation of the Radiative Properties of Polymeric Foams from Tomographic Images

Polymeric closed-cell foams are widely used in various applications where their insulating performance is of interest. In most of these applications, radiation propagation is an important mode of heat transfer. That is the reason why many studies have already been performed in the prediction of the radiative behavior. Until now, these studies were based on ideal representations of the cellular structure that simplify the real porous morphology. However, the recent development of x-ray tomography allows envisaging a noticeable improvement in the morphological characterization of these materials, which can be used to achieve a better numerical estimation of their radiative properties. To fulfill this objective, a numerical method for computing the directional radiative properties of particulate media based on ray-tracing procedures has been developed. The method to three-dimensional binary representations of the cellular structures obtained from x-ray tomography on plastic foams has been applied. The comparison between the spectral radiative properties computed by the simplified models of the literature and by our original models permits us to determine which assumptions are the most detrimental to the reliability of the simplified models.