Discrete Ordinates and Monte Carlo Methods for Radiative Transfer Simulation applied to CFD combustion modelling

Modelling radiative heat transfer in combustion applications involving complex geometries and detailed spectral properties of radiative gaseous species remains a difficult challenge, especially when full coupling with detailed chemistry and fluid dynamics is required. The Monte Carlo Method (MCM) usually considered as a reference ”exact” method for the computation of radiative transfer is however very demanding in CPU-time. An alternative is the Discrete Ordinates Method (DOM), based on a finite volume approach, that is more suitable for a direct coupling with CFD but may lack accuracy. The aim of the present paper is to propose and demonstrate the efficiency of a methodology for radiative transfer calculation, combining the advantages of both MCM and DOM. In this approach, the fast DOM is used to compute the radiative solution, whose accuracy is then controlled by comparison with the ”exact” MCM solution at a selection of controlling points. A first application of the proposed methodology to an industrial burner prototype shows its validity and potential for the direct coupling of radiation calculations with reacting flow computations.