The effect of thermal radiation using different models on methane–air flames combustion modelling using CFD

A two-dimensional axisymmetric RANS numerical model was used to examine the impact of thermal radiation using air stream radiation model on the generation of CO₂, NO, H₂O, O₂ and soot in turbulent methane diffusion flame. The extended Zeldovich mechanism and two transport equation models, respectively, were used to forecast the CO₂, NO, H₂O, O₂ and soot concentrations, while the turbulence-combustion interaction in the flame field was modeled in a k-ε/EDM framework. The projected spatial temperature gradients and published experimental data had a respectable level of agreement. It was discerned that the concentration of CH₄ has major impact on temperature, CO₂, NO, H₂O, O₂ and soot concentrations. The CO₂, and H₂O content increases as complete combustion is achieved due to adequate level oxygen at mid-section leading higher temperature generation and high NO generation. It was discovered that the flame production of NO and soot is significantly reduced when temperature is reduced using P1 radiation as opposed to the DO radiation model. By illustrating the spatial distribution of the NO content in the flame, such a phenomenon is addressed. Additionally, it was discovered that the temperature was related to a discernible decrease in soot generation. It was discovered that both models viz., P1 and DO, showed a similar trend that could be used for the predication of numerous ignition parameters.