A COMPUTATIONAL STUDY OF MULTI-BURNER ANNULAR AERO GAS TURBINE

摘要

In this study we present results from simulations of a single sector and a fully annular multi-burner aero engine combustor. The objectives are to facilitate the understanding of the flow, mixing and combustion to help improve the combustor design and the design process as well as to demonstrate that it is now feasible to perform high-fidelity re-acting flow simulations of full annular gas turbine combustors. The simulations are performed by a combustion Large Eddy Simulation (LES) model in which all flow features larger than the grid are resolved whereas the effects of the small scale flow features on the large ones are modeled. The LES method used is validated against a range of non-reacting and reacting flow configurations a few of which are reported here. The aero engine combustor of interest is here modeled both using a conventional single sector configuration and a fully annular multi-burner configuration and the Jet-A combustion chemistry is modeled by a global threestep mechanism. The single-sector and fully annular multi-burner predictions are similar but with the fully annular multi-burner configuration showing a different combustion dynamics and thus also somewhat different time-averaged profiles of the dependent variables. For the fully annular multi-burner configuration azimuthal pressure fluctuations are observed, resulting in successive reattachment and detachment of the flames in the azimuthal direction.