Chemical kinetics modelisation and LES combustion model effects on a perfectly premixed burner

Chemical kinetics modelisation and coupling with turbulent combustion models for compress-ible Large Eddy Simulations (LES) is a critical issue. Accurate flow predictions or pollutant emissions can only be guaranteed if the coupling is well mastered and understood. In a first attempt to qualify and understand the effet of each model, the case of a lean premixed swirled combustor with comprehensive measures is targeted (species mass fractions and temperature LES fields, averaged and RMS, are compared with experimental data). For the investigation, two turbulent combustion models are gauged. The first model relies on a presumed PDF ap-proach coupled to a look-up chemistry table obtained a priori with a reduced chemical scheme. The second model makes use of the thickened flame approach using the same reduced chemical scheme but with reaction rates that computed explicitly as the computations advances. Then, to estimate kinetic schemes reduction effects, the first model is compared to a third one, with the same PDF approach, but coupled to a look-up chemistry table obtained a priori with a complete chemical scheme. All LES are very close one to the other. The main difference between all relies on CO mass fractions. Although they are all able to return good outlet mass fractions, CO values inside the flame are better represented in the case of complex chemistry than in the case of reduced chemistry on one side, and with the PDF turbulent combustion model than with TFLES model on the other side