In DNS, all relevant scales are resolved, which allows for a detailed investigation of all processes.This also requires extensive computational resources. DNS provides more exact results that can be used to test more approximate models such as one finds in RANS or LES.Dynamic models coupling LES with reduced chemical kinetics will be investigated to take into account the local extinction and re-ignition phenomena. Laser-based methods will also be used to specify the flow dynamics and scalar dissipation.Aim: The aim is to develop models for turbulent premixed and partially premixed combustion under high swirl conditions and to use the developed numerical models to gain deeper understanding of premixed and partially premixed combustion process.LES models will be developed to couple detailed flamelet chemistry with level-set G-equation, accounting for stratified fuel/air mixtures. The work is also closely related to the gasturbine syngas combustion work (led by J. Content/Scope: Laser-based measurement techniques will be used for imaging of the wall surface temperature and the temperature in the gas.
Background: RANS-based models for turbulent flames suffer from the difficulty of modeling averaged chemical reaction terms (the “closure problem”).In contrast, LES-based models solve directly for the unsteady large scales by a filtering technique and only the remaining sub grid scales are modeled (SGS models).