Study of the non-gray-TRI effect on the turbulent methane combustion under O2/CO2 atmosphere

The radiative heat transfer dominates the major part of total heat transfer of turbulent methane combustion under O2/CO2 atmosphere, and accurate description of it is difficult but essential for improving the combustion simulation accuracy. Considering the large amount of participating media under O2/CO2 atmosphere and the remarkable turbulence-radiation interaction (TRI) effect, the weighted-sum-of-gray-gases (WSGG) model is adopted to calculate radiative properties of flue gas and the TRI effect is modeled (referred to as non-gray-TRI model). Based on the above model verified by experiment results of the relevant literature, the turbulent methane combustion under O2/CO2 atmosphere is simulated, and the accuracy of ignoring radiation or calculating by gray model, gray-TRI model and WSGG model are analyzed respectively. The results indicate that ignoring the radiation or using the gray model will produce substantial errors, and the TRI effect is not obvious when using the gray model. However, the TRI effect reduces the overall temperature of the combustion chamber when using the WSGG model. Therefore, the non-gray-TRI model is necessary to improve the simulation accuracy of turbulent methane combustion under O2/CO2 atmosphere.