Strategies for presumed PDF modeling for LES with premixed flamelet-generated manifolds

Abstract

Large Eddy Simulation is applied to a non-premixed bluff-body stabilized swirled methane-air flame of the Sydney flame series. The combustion chemistry is included via the so-called premixed flamelet-generated manifolds, being a progress variable approach based on steady premixed laminar flamelets. As turbulent mixing and chemistry interact on the subgrid scales, additional modeling of the probability density function of the mixture fraction and the progress variable is required. Two different approaches considering the statistical independence of these two quantities are presented. No large differences between these approaches were observed in a first computation, therefore, only one method was investigated in more detail. Radial profiles of velocity components and species obtained in the latter computation are compared with experimental data.

Keywords:

• large eddy simulation
• presumed PDF modeling
• turbulent combustion
• swirl flame

Acknowledgement

The LES computations were performed on the Hessian High Performance Computer (HHLR), which is supported by the High Performance Scientific Computing (HPSC) activity group, a member of the computational engineering center (FZCE) in Darmstadt. The authors gratefully acknowledge the German Research Foundation (DFG) for financial support through the collaborative research center 568.