Sparse-Lagrangian FDF simulations of Sandia Flame E with density coupling

Sparse-Lagrangian filtered density function (FDF) simulations are performed for Sandia flame E. A generalised multiple mapping conditioning (MMC) mixing model for the Lagrangian field enforces mixing localisation in the Eulerian large eddy simulation (LES) mixture fraction space. The modelled level of local extinction is determined by the appropriate pairing of mixing particles and the timescale of their mixing interaction. A major development presented in this paper is the inclusion of density coupling between the Eulerian LES and Lagrangian particle fields achieved through use of the equivalent enthalpy method adapted for sparse conditions. Results for two sparse simulation cases, one with one Lagrangian particle per eight Eulerian LES grid cells and the other with one particle per 32 Eulerian LES grid cells, show that accurate FDF predictions of passive and reactive scalars can be achieved for a relatively modest computational cost. (C) 2010 The Combustion Institute. Published by Elsevier Inc. All rights reserved.