Numerical analysis of pollutant formation and exhaust emission in a short annular combustor under part load operation

Abstract Emission characteristic of a single annular gas turbine combustor has been studied at engine part-load conditions from idle to max power setting. Under fuel-rich condition. The temperature field and pollutant formation at different power settings are studied in detail. The equivalence ratio varies from 0.35 corresponding idle power setting to maximum 1.1 at max power setting at take-off condition. Concentration of major pollutant species at combustor exit such as NOx, CO, CO 2 , soot, unburned hydrocarbons and water vapor are analyzed for varying inlet conditions and primary zone equivalence ratios at different power settings using model in ANSYS CFX. The pollutant concentrations are found to be increased at combustor exit with increase in power setting as equivalence ratio and flame temperature increase. The numerical predictions at low regime of power setting are validated against gas sampling data obtained from actual combustor testing in aerothermal test facility. The numerical analysis based on satisfactory validation with limited experimental data is very reasonable and provides input for prediction of pollutant emissions of the intended derivative engine during the landing-takeoff (LTO) cycle prior to engine test.