Numerical simulations of non-premixed turbulent combustion of CH4–H2 mixtures using the PDF approach

The present work is devoted to the study of non-premixed turbulent combustion with the PDF approach using three turbulence models: k-ɛ model, modified k-ɛ model and RSM model. A detailed kinetic mechanism is used in the numerical simulations. The three turbulence models are compared and evaluated with the experimental data and the numerical results of the literature. The evaluation concludes that the modified k-ɛ is the most appropriate for simulating this kind of flame. A study of the effect of hydrogen addition on methane combustion is performed. Hydrogen addition causes the elevation of combustion temperature, the decreasing of CO and CO2 mass fractions but leads to the increase of NO mass fraction.