DSGF solver for near-field radiative heat transfer: User guide

The discrete system Green's function (DSGF) method is a fluctuational electrodynamics-based numerical framework for predicting near-field radiative heat transfer (NFRHT) between three-dimensional thermal sources of arbitrary number, shape, size, and material. In the DSGF method, thermal sources are discretized into cubic subvolumes along a cubic lattice, and the system Green's functions between all subvolumes are obtained by solving a system of linear equations. From the system Green's functions, quantities of interest in heat transfer such as the power dissipated and the thermal conductance are calculated. The objective of this paper is to provide a user guide of the DSGF solver publicly available on GitHub. The basics of the DSGF method are first reviewed, followed by a detailed description of the DSGF solver implemented in MATLAB and C. The C implementation is parallelized and includes an iterative procedure which is not available in the MATLAB version. Example problems of NFRHT between two dipoles, two spheres, two cubes, and two membranes that can be used for verification are provided.