Parallel Solution Adaptive Scheme for Three-Dimensional Turbulent Diffusion Flames with Detailed Tabulated Chemistry

摘要

Mathematical modelling of the effects of turbulence on detailed-chemistry is an important issue in the accurate and reliable numerical prediction of turbulent combustion processes. The highly non-linear nature of both turbulence and chemistry make this extremely challenging. In this study, a Presumed Conditional Moment (PCM) approach, based on a β probability density function (PDF), is combined with the Flame Prolongation of ILDM (FPI) tabulation method to model the effects of turbulence and detailed-chemistry for diffusion flames. The recently proposed FPI scheme incorporates the effects of the detailed-chemistry on the local flow field for laminar flames through the use of two independent scalars: mixture fraction and progress variable and their variances. The Favre-Averaged Navier-Stokes (FANS) equations, based on the two-equation k-ω turbulence model, are used herein to model the effects of the unresolved turbulence on the mean flow field. The governing partial-differential equations for mean quantities are solved using a parallel, Adaptive Mesh Refinement (AMR), fully-coupled finite-volume formulation on body-fitted, multi-block, hexahedral mesh for three-dimensional flow geometries. Two approaches for coupling the PCM-FPI approach with the parallel AMR finite-volume solution method are considered. The PCM-FPI results are compared to experimental data for both reacting and non-reacting flows associated with a Sydney bluff-body burner configuration. The computational cost of the PCM-FPI scheme is compared to the cost of the simplified Eddy Dissipation Model (EDM). A full description of the proposed numerical solution scheme for turbulent non-premixed flames is provided along with an evaluation and demonstration of its computational performance and predictive capabilities.