Systematic analysis of lean-premixed swirl-stabilized combustion

A systematic data-analysis procedure is established to explore the underlying mechanisms responsible for driving unsteady flow motions in gas-turbine combustors. Various data processing and analysis approaches are developed and implemented. These include triple decomposition of flowfield, vortex identification, spectral analysis, linear acoustic modal and hydrodynamic stability analyses, and proper orthogonal decomposition. The work allows for a detailed investigation of the mechanisms of energy exchange between the mean, periodic, and turbulent flowfields in a combustion chamber, as well as their collective interactions with chemical heat release. As a specific example, the combustion dynamics in a lean-premixed swirl-stabilized combustor operating under a variety of conditions is carefully examined, based on an avalanche of time-resolved numerical data obtained from large-eddy simulations.