Large Eddy Simulation Of Gas Turbine Combustor Using Open FOAM

Recent developments in numerical schemes, turbulent combustion models and the regular increase of computing allow Large Eddy Simulation (LES) to be extensively used in numerical simulation of gas turbine combustor. In this paper, LES numerical formulation for real LPP burners is proposed, which adopts a one-equation subgrid scale turbulent model to handle the effect of the filtered subgrid scale eddies on the solved large scale eddies. In two-phase treatment, spray droplets are tracked using both Lagrangian method and Mento Carlo technique. The two-way coupling model based on SGS turbulent kinetic energy is used to model the mutual influences between SGS fluctuating velocity and the movement of spray droplets. Eddy-Dissipation-Model (EDM) is used to predict the temperature field and the Thickened Flame Combustion Model to predict self-ignition, flameout, backfire, pollution.A CFD code applied for large eddy simulation of gas turbine combustors has been developed in this thesis based on an open source CFD software OpenFOAM. In order to validate the precisions of the proposed models and the accuracy of the solver, a large eddy simulation of the classical Sommerfeld co-axial model combustor has been conducted and the predictions were compared with the experimental data. Good agreements were obtained, which demonstrate the reliability of the proposed models and the solver.The developed code was then applied to simulate the turbulent two-phase reacting flows in real gas turbine combustors. The selected computational domain is a sector structure which slices from an annular combustor. The predicted cold turbulent flow displays an apparent recirculation zone which is beneficial to the combustion organization. Turbulent fluctuations in combustor are picked up effectivity with the LES approach. The thermal temperature and velocity fields show a realistic combustion process. Combustion process occurs mainly in the head of the flame tube with benefit of the primary holes. Good cooling effects of the dilution holes reduce the outlet temperature to a reasonable level. The temperature distribution of the combustor outlet is compared to previous results and experimental data. The present predictions demonstrates the accuracy and reliability of the LES method.