A numerical study of combustion and NO_X emission characteristics of a lean premixed model gas turbine combustor

The combustion characteristics of a model gas-turbine combustor are investigated by performing 3-D Reynolds-averaged Navier-Stokes equations (RANS) simulations of swril-stabilized lean-premixed flames of methane/air for different equivalence ratio and swirler type. Their NO_X emission characteristics and thermal fatigue life are also elucidated with chemical reactor network (CRN) analysis and finite element analysis (FEA). To validate numerical models, the RANS simulations results are compared to experimental data, which shows reasonable agreement between them. The CRN analysis reveals that the amount of NO_X can be reduced by low temperature and short residence time. The FEA identifies areas vulnerable to thermal fatigue. The largest strain amplitude is observed at a single nozzle exit because of large temperature variation and complicated structure. The cycles to failure at the vulnerable regions are estimated using the ε-N curve of AISI type 304 stainless steel.