A rigorous asymptotic perspective on the large scale simulations of turbulent premixed flames

An idealized model for turbulent premixed flames is introduced. It consists of a scalar advection-reaction-diffusion equation that describes the interaction of a thin flame with a turbulent-like flow field acting on two separate scales. Rigorous asymptotic results as well as affordable and reliable direct numerical simulations are available to predict the effective large scale behavior of the idealized front. This framework is used as part of a strategy to validate a modeling approach for the large scale simulations of turbulent premixed flame fronts. The relevance to practical computations is demonstrated by addressing three important issues regarding closure models for more realistic turbulent flames: scaling regimes in the parameterization of the flame speed; relationship between the front at large scales and the resolved reaction zone in a direct simulation; accuracy and efficiency of the large scale flamelet approach.