Large Eddy Simulation and Modal Analysis of the Dual Independent Swirl Combustor

Modern gas turbine systems face increased constraints from economic and environmental perspectives. These limits have pushed operations into instability-prone design points. To study the underlying physics and develop strategies to mitigate these issues, a laboratory-based gas turbine model combustor has been developed at the University of Michigan. This new combustor features a dual swirler setup with large, independently fed plenums with transverse fuel injection designed for studying active control strategies for gas turbine systems with an integrated control system. In this work, LES reacting flow simulations are conducted, and the simulations are validated against experimentally measured pressure signals, chemiluminescence imaging, and unsteady high-frequency PIV. The dynamics of coherent structures are studied using Koopman analysis. This work is part of an initiative to develop reduced models for use in the design of an active control strategy to suppress combustion instabilities.