Thicked Laminar Premixed Flame Structure Analysis Based on Multistep Reaction Mechanism

Thickened flame (TF) model is one of the effective methods to simulate combustion phenomenon. Theoretically, it could be extended to multi-step chemical reaction mechanism. In this work, the freely propagating planer flames with various thickening factor are simulated using TF model. The solver is developed based on OpenFOAM. The results shown that TF model coupled with multi-step mechanism will underestimate burnt gas temperature. Meanwhile, some post-flame species (CO, OH) concentration are overestimated, which means the decrease in burnt gas temperature is mainly caused by enhanced species diffusion. Dynamic thickened flame (DTF) model coupled with multi-step mechanism performs well for predicting species concentration and combustion state. So it is not recommended to use TF model coupled with a multi-step chemical reaction mechanism.