A flamelet time scale model for non-premixed combustion including chemical kinetic effects

Abstract

Many flamelet models for turbulent non-premixed combustion assume that a turbulent diffusion flame behaves locally as a steady, one-dimensional, laminar, strained flame. While this assumption works well in many practical applications, it fails to take into account unsteady chemical kinetic effects that occur at low Damköhler numbers. Commonly used methods to account for unsteady effects are the RIF formulation [1] and conditional moment closure models [2]. These models are computationally expensive, as equations for detailed chemistry must be solved. A new, efficient, flamelet based model that incorporates unsteady effects is proposed.