Numerical Simulation to Characterize Homogeneity of Air-Fuel Mixture for Premixed Combustion in Gas Turbine Combustor

Homogeneity in mixing of air and fuel in premixed combustion for a gas turbine combustor is a critical criterion to ensure efficient combustion and less environmental hazards. The current work deals with determining this homogenous characteristic of air-fuel mixture through computational simulation to specify homogeneity for a particular premixing length and equivalence ratio required for gas turbine combustion. A 3-D geometry of combustion chamber with combustion zone of internal diameter 6 cm is constructed. A premixing tube is augmented with the combustion chamber which has one air inlet port at the bottom and 3 fuel inlet ports. Air-fuel mixture is considered to enter the combustion zone with inlet swirl. The homogeneity of the mixture is found out at the dump plane and other important planes from simulation done with ANSYS FLUENT^® for the meshed geometry. The results show whether mixing of air and fuel is full or partial and the extent of partial premixing. The parameters varied in the ANSYS FLUENT^®. based simulation are the premixing length i.e. port of entry of fuel, the fuel flow rate i.e. the equivalence ratio and the air flow rate.