A Premixed Turbulent Flame Structure Model Having Reactant Islands and Fractal Flame Surfaces : Formulation and Test of the Model

Abstract

A model for the premixed turbulent flame structure has been developed in which the flame zone of a turbulent flame is composed of two parts: a wrinkled flame front and some island flamelets behind it. Their fractions are supposed to vary continuously according to a proposed function of u'/S_LO, where u' is the turbulence intensity and S_LO is the laminar burning velocity. All flamelets were assumed to be fractal ones. The concepts of "flame thickness" and "transition time" for laminar flames were introduced into the model for turbulent flames. The model provides not only the structural parameters, but also the burning velocities of turbulent flames.