LES-CMC and LES-Flamelet simulation of non-premixed methane flame (Sandia F)

In this paper, the Large Eddy Simulation (LES) together with the Conditional Moment Closure (CMC) and flamelet combustion models have been applied for modelling of methane flame Sandia F. In the case of the CMC model, both instantaneous and time averaged values predicted numerically agree well with measurements. Attention was devoted to modelling aspects of the conditional scalar dissipation rate (SDR), which is a key quantity of the CMC approach. The two methods of computing SDR are compared with emphasis on a correct prediction of localised extinctions and on their influence on the mean values. It was found that the method of modelling of SDR has rather minor impact on the instantaneous values, whereas larger differences were observed in statistics. In the case of the flamelet model, although it is not able to predict extinctions and re-ignition, the mean values were in good agreement with the experiment.