Modelling and analysis of fluid flow problems coupled with radiative heat transfer

Abstract

Combustion plays a fundamental role in society, being one of the primary means of energy conversion and storage, with countless applications. As such, it is a key topic in engineering and industrial processes. In many cases, combustion and thermal radiation occur simultaneously: the high temperatures resulting from exothermic reactions, as well as the radiative interaction of the gases generated from these reactions, create an environment where complex radiative heat transfer takes place. Therefore, coupling CFD with radiative heat transfer models is essential for the accurate simulation of industrial reactive flows. Furthermore, literature shows that thermal radiation can significantly affect heat transfer in other situations, such as in thermal cavities at ambient temperature, a problem that is frequently studied without considering radiation effects. This work presents the development and benchmarking of a coupling between a CFD software (MFSim) and a radiative heat transfer solver for participating media (RTS), both internally developed by MFLab in the Federal University of Uberlândia. MFSim is a robust simulation package, capable of modelling turbulence, heat transfer, fluid–structure interactions, reacting flows, and Lagrangian particle transport. RTS is capable of modelling radiative transfer in gray and non-gray participating media containing gases like CO2 and H2O, as well as isotropic and anisotropic scattering phenomena. By integrating these codes, the extensive set of physical models available in MFSim, designed to simulate complex engineering problems, now includes radiative heat transfer, enabling more realistic and accurate modelling of combustion processes. The coupling employs distinct meshes for CFD and radiation, connected via interpolation, allowing for more computational efficiency, as radiative models do not usually require the same spatial resolution as CFD. Tests have shown that the interpolation layer between both algorithms has relatively low computational cost. Benchmarks performed on canonical cases show good agreement with the literature, verifying the approach and reinforcing the importance of radiation in heat transfer simulations.