Modeling and numerical simulation of a pilot-stabilized turbulent premixed flame

The present paper is devoted to the numerical modeling of turbulent reactive flows subjected to spatial variations of equivalence ratio.In such situations, the description of the local thermochemistry requires at least two variables. The mixture fraction and the fuel mass fraction are respectively chosen to describe the composition of the fresh mixture and the chemical reaction progress. In the present contribution, a generalization of the Libby-Williams (LW) approach to four delta probability density function (Pdf) is presented. Transport equations for the first and second-order (variance) of mean scalar quantities are numerically solved. Moreover, the so-called LW-P model
solves an additional transport equation for the cross-correlation between the reactive and the passive scalars. The model is applied to the calculation of a turbulent lean-premixed flow of methane and air stabilized by a near-stoichiometric pilot-flame. Numerical results regarding flow dynamics and flame structure are compared with the experimental data of a laboratory-scale burner-chamber device.