Development of Unified Flame Surface Density Based Reaction Rate Models for the LES of Turbulent Premixed Flames

We aim to develop an efficient Flame Surface Density (FSD) based reaction rate closure for the Large Eddy Simulation (LES) of turbulent premixed flames. Although FSD closures are well established for Reynolds Averaged Navier Stokes (RANS) simulations, they are relatively rare for LES, and no detailed evaluation of their performance is available so far. In this project, FSD based reaction rate closures will be developed and simultaneously assessed by a-priori analyses of explicitly filtered Direct Numerical Simulation (DNS) data, and a-posteriori evaluations of model performances in actual LES results, in a configuration for which experimental data is available. Based on the simultaneous a-priori and a-posteriori analyses, new unified models will be developed and their performance will then be assessed by the same analysis as carried out for the existing models. The model implementation will then be generalised in such a format that they can be used as an add-on to any commercial or inhouse general purpose code involving complex geometrical configurations. The new subroutines where this will be implemented will be made freely available to interested national and international colleagues. An efficient FSD-based reaction rate closure will provide a reliable CFD based design tool for reliable, cleaner and cost-effective combustion devices where combustion takes place in premixed mode (e.g. Spark Ignition engines, Lean Premixed Pre-vaporised (LPP) and industrial gas turbine combustors.)