LARGE EDDY SIMULATION OF A REALISTIC GAS TURBINE COMBUSTOR

This paper proposes a large eddy simulation approach for the modeling of combusting flow with spray in realistic gas turbine combustors. A one equation subgrid model is used to model the effect of the unresolved subgrid scales on the resolved large scales. Subgrid combustion is modeled by an extended eddy dissipation model in which the filtered reaction rate is controlled by the turbulent mixing rate between the fine structures and the surrounding fluids. An Eulerian-Lagrangian approach is used to model the two-phase spray flow, and spray particles are tracked by a two-way coupling Lagrangian approach. Then the proposed approach is applied to simulate a combusting spray flow in an industrial annular combustor. The objectives of this study are to demonstrate its capability to investigate the complex flow and combustion dynamics in realistic gas turbine combustors. The predicted instantaneous and time averaged fields of velocity, temperature, pressure, fuel mass fraction are investigated. The precessing vortex core caused by the swirling flow as well as pressure oscillations is examined The predicted results nicely reproduce the flow, spray and combustion dynamics and successfully capture the main features of the studied combustor, such as the processing vortex core. Finally, the predicted exit temperature and the total pressure loss are compared with experimental data and good agreements are obtained.