[2011.07588] A normal-diffusion theory for near-field radiative heat transfer in dense nanoparticle systemsopen searchopen navigation menucontact arXivsubscribe to arXiv mailings
We derived a normal-diffusion type governing equation for near-field radiative heat transfer (NFRHT) in dense nanoparticle systems at continuum-scale directly from fluctuational electrodynamics formulation at particle-scale. The near-field radiative thermal conductivity (NFRTC) tensor is discovered naturally as the coefficient of diffusion term, which results in a new formula for calculating NFRTC. A first-order term is shown to appear in the governing equation, which reveals a convection-like transfer behavior of NFRHT in highly asymmetrical systems of particles. For systems of uniformly distributed particles, the governing equation reduces to the classical heat diffusion equation. This work rigorously builds a bridge between particle-scale and continuum-scale NFRHT in particulate system, which paves a way for understanding and analysis of heat diffusion in large-scale particulate system with near-field interaction.