Numerical simulation of fuel-rich methane turbulent diffusion flames

We applied a three-step reduced mechanism that is introduced from a detailed mechanism to calculate fuel-rich methane-air turbulent diffusion flame characteristics for the purpose of saving calculation time. We obtain good agreement between calculated and measured values on temperature, carbon monoxide, and carbon dioxide distributions in the combustor except for the near flame front. It is hard to calculate very perturbed areas like a flame front because the k-epsilon 2-equation model, used in this calculation, is modeled based on isotropic turbulence and isothermal fields. We also obtain good agreement carbon monoxide distribution, which was formed well in fuel-rich conditions by using three -step reduced mechanism. It is impossible to calculate carbon monoxide distribution by using one-step reduced mechanism, which is mainly used on combustion simulation. For the above reason, numerical simulation using three-step reduced mechanism is a more effective method to calculate the characteristics of turbulent diffusion flame because it is able to calculate a local fuel-rich condition.