Modeling near-field radiative heat transfer from sharp objects using a general 3d numerical scattering technique

TL;DR

This paper introduces a general 3D numerical scattering method to accurately model near-field radiative heat transfer from sharp objects, revealing unique flux profiles and scaling laws for conical shapes.

Contribution

It develops a versatile scattering-theory-based boundary-element method for precise heat transfer predictions involving complex 3D geometries with tips or corners.

Findings

Distinct scaling laws for conical objects at small separations

Sharp cones show a local minimum in heat flux below the tip

Method applicable to arbitrary 3D shapes

Abstract

We examine the non-equilibrium radiative heat transfer between a plate and finite cylinders and cones, making the first accurate theoretical predictions for the total heat transfer and the spatial heat flux profile for three-dimensional compact objects including corners or tips. We find qualitatively different scaling laws for conical shapes at small separations, and in contrast to a flat/slightly-curved object, a sharp cone exhibits a local \emph{minimum} in the spatially resolved heat flux directly below the tip. The method we develop, in which a scattering-theory formulation of thermal transfer is combined with a boundary-element method for computing scattering matrices, can be applied to three-dimensional objects of arbitrary shape.