Direct Numerical Simulation of a Statistically Stationary Turbulent Lean Methane-Air Bunsen Flame

摘要

Direct numerical simulation of a three-dimensional spatially-developing turbulent slot-burner Bunsen flame has been performed using detailed methane-air chemistry. The simulation is performed for three flow through times, long enough to achieve statistical stationarity. The turbulence parameters have been chosen such that the combustion occurs in the thin reaction zones regime of premixed combustion. The data is analyzed to study possible influences of turbulence on the structure of the preheat and reaction zones. The results show that the mean thickness of the turbulent flame is greater than the corresponding laminar flame. Also, the effects of flow straining and flame front curvature on the mean flame thickness are quantified through conditional means of the thickness.