Juliacon 2024

Radiation occurs everywhere at all times. In high temperature environments it can be the dominant mode of heat transfer. It is highly relevant to climate sciences. In engineering it is especially relevant to aerospace and space exploration for propulsion while also being crucial in power generation and boiler design. Solving heat transfer problems involving combustion is notoriously difficult, partly because the combustion products participate in the radiative heat transfer. The added complexity of a participating medium is described by the Radiative Transfer Equation (RTE) which is an integro-differential equation in seven independent variables: three spatial, one temporal, two directional and one spectral. RayTraceHeatTransfer.jl solves the RTE (neglecting temporal and spectral dependencies) in a user defined geometry. As the first step the user specifies the bounding geometry. The geometry is then meshed into the desired resolution. Next, Monte Carlo ray tracing is performed by sampling ray emissions from every zone in the geometry and following the ray bundles throughout the domain. The points of emission and absorption are recorded in four Exchange Factor matrices. These matrices describe the 'connectivity' of the domain for the specified properties of the participating medium. Using the Exchange Factor matrices heat transfer problems can be solved efficiently using a variation of the Zonal Method, without the need for repeated ray tracing in the same geometry. In order to solve the heat transfer problem, either a temperature or a heat flux must be specified for each element in the geometry (surface or volume). Then the solution to the heat transfer problem returns the remaining temperatures and heat fluxes. As a last feature of the package the user can automatically measure the validity of the solution in a square domain against the analytical solution of the RTE of Crosbie and Schrenker (1982).