General formulation of coupled radiative and conductive heat transfer between compact bodies

TL;DR

This paper introduces a comprehensive framework combining radiative and conductive heat transfer for arbitrarily shaped bodies at sub-wavelength distances, revealing large radiative transfer rates and nonlinear temperature profiles in nanostructures.

Contribution

It develops a macroscopic coupled model integrating fluctuating volume-current method with Fourier conduction, applicable to complex geometries and materials.

Findings

Radiative heat transfer rates can be twenty times larger than in planar geometries.

Bulk plasmon resonances significantly enhance radiative transfer.

Coupling of radiative and conductive transport leads to nonlinear temperature profiles.

Abstract

We present a general framework for studying strongly coupled radiative and conductive heat transfer between arbitrarily shaped bodies separated by sub-wavelength distances. Our formulation is based on a macroscopic approach that couples our recent fluctuating volume--current (FVC) method of near-field heat transfer to the more well known Fourier conduction transport equation. We apply our technique to consider heat exchange between aluminum-zinc oxide nanorods and show that the presence of bulk plasmon resonances can result in extremely large radiative heat transfer rates (roughly twenty times larger than observed in planar geometries), whose interplay with conductive transport leads to nonlinear temperature profiles along the nanorods.