Numerical Study of Two Reaction Mechanisms on Delft Flame III Using Large Eddy Simulation and Conditional Moment Closure Approach

A conditional moment closure model is adopted together with a state-of- the-art LES approach to simulate the target flame of the TNF workshop, Delft piloted methane flame III. For modeling the sub-grid scales, the constant Smagorinky model is used in this study. First order conditional moment closure is used to model the turbulence-chemistry interaction. To calculate the conditional velocity and the conditional scalar dissipation, conditional volume averaging with smoothing is used. To study the effect of the chemistry, two different methane reaction mechanisms are used. The first reaction mechanism is the one-step methane chemistry with 4 species and 1 reaction. The second reaction mechanism is the Smooke reaction mechanism which consists of 16 species and 25 reactions. A second order time accurate predictor-corrector method is used for time integration of the Favre filtered Navier-Stokes equations. It is shown that the reaction mechanisms has almost no influence on velocity and scalar fields. However, the temperature field is influenced by using a more complex reaction mechanism.