粒子系辐射换热是典型的参与性介质辐射换热问题，然而经典的辐射传递理论对粒子的散射按照远场处理，仅适用于粒子随机分布的稀疏粒子系。当粒子平均间隔相当或小于热辐射波长时，即稠密粒子系情形，辐射换热以近场为主并存在复杂的多体相互作用。目前稠密粒子系辐射换热特性及规律还知之甚少。为解决稠密粒子系辐射换热所面临的经典辐射传递理论局限的难题，本项目基于辐射换热严格理论(热辐射第一原理)，研究当邻近粒子处于近场区时粒子系的辐射换热，全面考虑各种近场换热机制。将揭示稠密粒子系辐射换热的特性和规律，厘清多体作用强化或抑制换热量的机制和产生条件，发展能够考虑粒子近场作用的宏观体系辐射换热分析理论，为将近场辐射换热理论应用于工程实际问题建立通路，并在实验上研究近场辐射换热对稠密粒子系等效导热系数的贡献，对多体辐射换热理论进行检验。研究成果将为稠密粒子系在高温传热介质、增材制造等技术中的传热分析提供基础理论支持。

Radiative heat transfer in particulate system is a typical problem of radiative heat transfer in participating media. However, the classical radiative transfer theory is only suitable for the analysis of heat transfer in random dilute particulate system, due to it treats the light scattering by particles as far field process. If the mean particle separation distance is comparable or smaller than thermal radiation wavelength, namely, the case of dense particulate system (DPS), radiative heat transfer will be dominated by near field mode and complex many body interactions among particles will exist. Currently, knowledge of the characteristics and laws of radiative heat transfer in DPS is still scarce. In order to solve the faced problem of limitations of classic radiative heat transfer theory in dealing with DPS, this project will study radiative heat transfer in particulate system in case the neighboring particle separation distance is in the near field, based on the rigorous theory of radiative heat transfer (first principle of thermal radiation), then all the near field mechanism of radiative heat transfer can be fully considered. This study will explore the characteristics and laws of radiative heat transfer in DPS, make clear the mechanism and conditions of enhancement and inhibition of of exchanged heat flux by many body interactions, develop near field radiative heat transfer theory that can deal with macro-scale system, build a road between the theory of near field radiative heat transfer and the practical problems in engineering, experimentally study the contribution of near field heat transfer on the effective thermal conductivity of DPS, and make verification of the many body radiative heat transfer theory. The output of this study will provide basic theoretical support for the applications DPS in technologies such as high temperature heat transfer medium, additive manufacturing, etc.