Comparison of some global chemical kinetics effects on methane lifted flame 3D simulation

In the present study, the effects of several global chemical kinetics in 3-dimensional numerical simulation of methane combustion in a horizontal combustion chamber which has lifted flame by a set of open source code OpenFOAM, is compared. The purpose of this comparison is to study the effects of 1, 2 and 4 step global kinetics on velocity, temperature and species distribution. In this simulation, conservation and state equations are solved simultaneously. Partial differential equations are discreted by finite volume method. The effects of turbulence by standard k-e, radiation by P1 model and turbulence-combustion interaction by PaSR are modeled. The results of numerical simulations have been validated by a cylindrical combustion chamber experimental data. The results show that the kinetics have considerable differences in results of velocity, temperature and species in the final third of the chamber where the flame is located, and differently predict locations of the flame. According to these results, 4-step mechanisms were more accurate than the 2-step type. Between 4 step mechanisms, JL is more accurate than Kim in overall; However, its calculation time is higher than the Kim. Single step kinetics were not able to keep the lifted flame.Towards the experimental results, 2-step model predicts the flame in downward and Kim mechanism estimates the flame in the upward.