LES-FGM of Hydrogen Enriched Jet in Crossflow Flames

Abstract The flamelet generated manifold (FGM) method has been successfully used by the gas turbine industry and research community for modeling of gas turbine combustion. However, LES (Large Eddy Simulation) with FGM modeling for hydrogen and hydrogen enriched fuels needs more careful consideration to account for its high reactivity and diffusivity and it merits revisiting the FGM modeling setup. In this study, LES-FGM simulations of hydrogen combustion for micromix fuel injection using a commercial CFD code, STAR-CCM+ is presented. The assessment characterizes hydrogen combustion at elevated temperature and pressure that is representative of gas turbine conditions. Sensitivity studies for a range of FGM modeling parameters, focused on turbulent Schmidt number in transport equations and chemical kinetics mechanisms were conducted. Newly developed reduced chemical kinetics mechanisms derived specifically for hydrogen and hydrogen and natural gas fuel mixtures up to 20 bar and 2200 K were considered. The LES results for different FGM set-ups and chemical kinetics models were compared against test data obtained from a jet in crossflow (JICF) geometry for hydrogen enriched fuel at high pressure, this experimental study was conducted by German Aerospace Center, DLR [1,2]. The LES results showed good agreement with test data, both OH PLIF measurements and velocity profile data.