Comparison of the gray gas and the SLW radiation models in the simulation of a steady-state methane-air diffusion flame
Anderson Mossi, Vinayak Barve, Marcelo Galarça, Horacio Vielmo, Francis França, and Ofodike Ezekoye
Accurate prediction of the radiative heat transfer is of great importance in simulations of combustion processes. To compute the total radiative transfer, it is necessary to integrate the radiative transfer equation (RTE) over the entire wavelength spectrum, a highly time consuming task that still demands the use of gas models. In this work, a finite volume code is used to simulate a steady-state methane-air diffusion flame. The code solves the equations for the conservation of mass, momentum, individual species and energy. The solution also includes a chemistry model for the formation of soot, which is of major importance in the computation of the radiation heat transfer. The radiation exchanges are computed by the discrete ordinates method, and using two different approaches: the gray gas model and the spectral-line based weighted-sum-of-grays-gases (SLW) model. The results for the temperature distribution, gas species concentration, and soot formation are examined with the two different radiation gas models used.
Keywords: Radiation heat transfer, spectral models, combustion, diffusion flames, soot formation.