Large eddy simulation (LES) is conducted of a turbulent piloted nonpremixed methane jet flame. This flame has been studied experimentally at Sandia National Laboratories. The subgrid scale (SGS) closure in LES is based on the scalar filtered mass density function (SFMDF) methodology. The SFMDF is essentially the mass weighted probability density function (PDF) of the SGS scalar quantities. The SFMDF is obtained from an exact transport equation which provides a closed form for the chemical reaction effects. The unclosed terms in this equation are modeled by a set of stochastic differential equations (SDEs). The SDEs are solved by a hybrid finite-difference/Lagrangian Monte Carlo procedure. This flame exhibits little local extinction. In previous work, the instantaneous flame composition was related to the mixture fraction based on the flamelet model at low strain rates. In the present work, this assumption is relaxed, and a direct solver is employed for finite-rate chemistry. The results via this method agree favorably with those obtained experimentally. The end result is an accurate and affordable method for the LES of realistic turbulent flames.
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