Numerical simulation of cellular flame propagation in narrow gaps

A computational model for combustion of premixed gases in narrow gaps between parallel plates is presented. The model is based on the numerical solution of conservation equations for multicomponent reacting gas flow in the small Mach number approximation. Detailed kinetic mechanism is used to describe combustion reactions. A block structured adaptive mesh refinement algorithm is applied in order to increase resolution in the high-gradient flow regions, mainly near the flame front. Simulations are performed by the software ParTCS-3D developed by the authors, using the high-performance platform K-100 installed in Keldysh Institute of Applied Mathematics. The efficiency of the parallel implementation of the developed numerical technique is demonstrated. Parametric study is presented in combustion of stoichiometric methane-air mixture, the distance between the plates was varied in the range 3–6 mm. Development of propagating flame instability leading to the formation of cells on the flame front is demonstrated. At small gap width, flame extinction is obtained at a small distance from the ignition source. A dependence of visible flame propagation speed on the gap width is obtained, revealing faster flame propagation in wider gaps due to weaker effects of viscosity and heat losses. The numerical efficiency of the use of structured adaptive hierarchical grids for simulation reacting gas flows, which is characterized by the presence of relatively narrow zones of the reaction (flame fronts), is shown.