Large Eddy Simulation of Combustion Systems at Gas Turbine Conditions

Abstract

Three different aspects of Large Eddy Simulation (LES) of combustion processes are covered in this chapter. All three are based on using tabulated chemistry models to cover the chemical reactions occurring in gas turbines. The chosen approaches are all based on flamelet models. One part of the work deals with the investigation of subgrid scale models using Transported Eulerian Monte Carlo Probability Density Function (PDF) methods. The chemistry is dealt with using non-premixed flamelets and premixed Flamelet Generated Manifolds (FGM). The second aspect covered is the extension of the FGM method towards premixed flames where unresolved subgrid flame structures need to be handled. Therefore, the FGM approach was coupled with the Artificially Thickened Flames (ATF) model. The third aspect of combustion LES discussed here deals with the inclusion of more detailed reaction kinetics in the FGM approach in order to better predict minor species like nitric oxides or carbon monoxide, which are important development goals in today’s gas turbine industry. As all three aspects discussed in this chapter are located on the smallest scales in a combustion system, either the flow or flame subgrid structures, they are closely related to each other.