FIVER: An open-source tool solving unsteady radiative-conductive heat transfer problems in complex media and geometries

Heat transfer problems involving temperatures above about 500 °C are central to many important industrial fields, but are challenging to solve, as radiative exchange becomes the dominant mode of heat transfer in these conditions. Such challenges are exacerbated when dealing with media participating in the radiative exchange, like semitransparent materials (e.g., silicate glasses), specific gases (e.g. steam and CO 2 ), and complex structures (e.g., foams and lattices). Open-source and general-purpose simulation tools tackling similar heat transfer problems are currently not available. Here we present a first effort to bridge this gap, introducing FIVER (FInite VolumE Ray tracer), an open-source MATLAB® tool implementing a collision-based, forward, discrete Monte Carlo ray tracing method on structured voxel grids. FIVER can model spectral radiation and properties, participating media, and refractive surfaces in complex 3D domains. The ray tracer is coupled with a finite-volume solver which, in this first release, allows FIVER to solve unsteady radiative-conductive heat transfer problems. We validate FIVER against two literature cases with participating spectral media. FIVER can accelerate the development of key high-temperature technologies, like those involved in the decarbonization of industrial processes. We hope it will serve as a valuable tool to researchers active in this field and to the heat transfer community in general. • FIVER (FInite VolumE Ray tracer) is an open-source andgeneral-purpose simulation tool. • FIVER solves radiative-conductive problems in participating media and complex geometries. • FIVER is validated against two literature cases involvingparticipating spectral media.