The IRST model for turbulent premixed non-adiabatic methane flames

A model is presented to predict turbulent non-adiabatic premixed combustion of methane under gas turbine conditions. Chemical reaction and heat loss a re described with four independent scalar variables. These are the enthalpy variable and three reaction progress variables for combustion of methane, hydrogen and carbon monoxide. In the combustion model turbulence is taken i nto account by weighting with an assumed shape PDE The model is used to cal culate a 32 kW methane flame in an air cooled combustion chamber. The calcu lated CO, CO2, O-2 and NOx concentrations are compared with suction probe m easurements at several locations in the combustion chamber. The non-adiabat ic calculations and the measurements show good agreement. Adiabatic calcula tions show a significant overprediction of NO. Radial profiles of mean axia l velocity and turbulent kinetic energy were measured with a 2D LDA system. The measurements show a good agreement. It is concluded that the non-adiab atic model is necessary and suitable to predict NO formation in turbulent p remixed methane flames with heat loss.