Some Basic Issues of the Averaged G-Equation Approach to Premixed Turbulent Combustion Modeling

ABSTRACT

In a recently developed and widely used premixed turbulent flame model, the so-called G-equation is averaged and combined with a balance equation for the variance G􀀂2 􀀃 (G 􀀁 G)2 , where G is an averaged G-field. The goal of this communication is to discuss certain basic issues relevant to the G - and 2 G􀀁 -equations and, in particular, to stress that the latter equation is ill defined, because the G- and G -equations are physically meaningful at different surfaces. Moreover, by analyzing simple examples, it is shown that a widely accepted association of the scalar G with the so-called distance function does not allow us to consider the G-equation to be physically meaningful in the entire flow field.