Continuum approach based on radiation distribution function for radiative heat transfer in densely packed particulate system

TL;DR

This paper introduces a new continuum approach based on radiation distribution functions to model radiative heat transfer in densely packed particulate systems, addressing limitations of traditional radiative transfer equations in non-random arrangements.

Contribution

It proposes a novel continuum model using radiation distribution functions that effectively captures radiative transfer in densely packed, non-random particulate systems without relying on the traditional RTE.

Findings

The radiation distribution function is anisotropic in regularly packed systems.

The continuum model accurately predicts temperature distribution in dense particulate media.

The approach outperforms traditional methods in non-random particulate arrangements.

Abstract

The study of radiative heat transfer in particulate system is usually based on radiative transfer equation (RTE) with effective radiative properties. However, for non-random, densely and regularly packed particulate systems, the applicability of RTE is questionable due to dependent scattering and weak randomness of particle arrangement. In this paper, a new continuum approach that does not explicitly rely on the RTE is proposed for radiative heat transfer in the densely packed particulate system. The new approach is based on the generalization of the concept of radiation distribution factor (RD) at discrete scale (or particle scale) to radiation distribution function (RDF) at continuum scale. The derived governing equation is in integral form, with RDF as the continuum scale physical parameter that characterize the radiative transfer properties of the system. The characteristics of the RDF for different particulate system (randomly or regularly packed) are studied. The RDF in regularly distributed particulate system is shown to be anisotropic. The continuum approach is verified by using heat transfer simulation at the particle scale, and demonstrated to have excellent performance in predicting the temperature distribution in dense particulate system. This work provides an alternative continuum theory, which will help the analysis and understanding of radiative heat transfer in densely packed media.