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ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
NUMERICAL SIMULATION OF RADIATIVE TRANSFER IN HETEROGENEOUS MATERIALS WITH A NULL-COLLISION MONTE CARLO ALGORITHM
Submission Author:
Priscila Sousa , MG
Co-Authors:
Agnes DELMAS, Maxime Roger
Presenter: Priscila Sousa
doi://10.26678/ABCM.ENCIT2016.CIT2016-0471
Abstract
Many materials have a heterogeneous structure due to their use and function in various industrial applications. Radiative transfer has a relevant impact in such media because of this structure. For instance, porous or fibrous ceramics used as thermal barriers coating in the spatial field or as protection of dawns of gas turbines constitute a participating media for radiative transfer. Modeling radiative transfer in heterogeneous media requires generally a homogenization model for the radiative properties. In those approaches, equivalent homogeneous radiative properties (such as the absorption and scattering coefficients or the phase function parameters) are used to estimate radiative transfer. Some assumptions such as Beerian medium may not be valid anymore in those equivalent homogeneous medium and requires complicated model for radiative transfer. One of the main strengths of the Monte Carlo - Null Collision algorithm presented in this work is its ability to predict radiative transfer in heterogeneous media without homogenization model, since a statistical approach is used for the treatments of the heterogeneities. A numerical code based on this algorithm has been developed. It solves the Radiative Transfer Equation (RTE) in a heterogeneous emitting, absorbing and scattering material, and the Lorenz-Mie model is used for calculating the radiative properties of the heterogeneities (pores, fibres or particles). The comparison between the predicted and measured emission for a porous alumina sample (Al2O3) at 820K is presented in this work. Radiative emission measurement are performed on an experimental set-up developed for high-temperature infrared spectrometry (FTIR) emission measurements.
Keywords
Radiative transfer model, heterogeneous media, Monte Carlo, Null Collision, spectrometry
