A computational tool for the detailed kinetic modeling of laminar flames: Application to C2H4/CH4 coflow flames

In this work a new computational framework for the modeling of multi-dimensional laminar flames with detailed gas-phase kinetic mechanisms is presented. The proposed approach is based on the operatorsplitting technique, in order to exploit the best numerical methods available for the treatment of reacting, stiff processes. The main novelty is represented by the adoption of the open-source OpenFOAM code to manage the spatial discretization of the governing equations on complex geometries. The resulting computational framework, called laminarSMOKE, is suitable both for steady-state and unsteady flows and for structured and unstructured meshes. In contrast to other existing codes, it is released as an open-source code and open to the contributions from the combustion community. The code was validated on several steady-state, coflow diffusion flames (fed with H2, CH4 and C2H4), widely studied in the literature, both experimentally and computationally. The numerical simulations showed a satisfactory agreement with the experimental data, demonstrating the feasibility and the accuracy of the suggested methodology. Then, the C2H4/CH4 laminar coflow flames experimentally studied by Roesler et al. [J.F. Roesler et al., Combust. Flame 134 (2003) 249–260] were numerically simulated using a detailed kinetic mechanism (with 220 species and 6800 reactions), in order to investigate the effect of methane content on the formation of aromatic hydrocarbons. Model predictions were able to follow the synergistic effect of the addition of methane in ethylene combustion on the formation of benzene (and consequently PAH and soot).