Global stability analysis of isothermal swirling flow in a model combustion chamber

This paper presents the linear stability analysis of a swirling flow in a model combustion chamber. The flow features a strongly coherent component associated with vortex core precession. Global stability analysis was performed on the mean field obtained via the large eddy simulations, incorporating turbulent viscosity. The eigenvalue spectrum revealed a mode with a dimensionless frequency of 0.76. Its eigenfunction distributions indicated that this mode corresponds to a precessing vortex core (PVC). These findings confirms that the PVC is a global unstable mode developing in a mean turbulent flow and will serve as a basis for further work on the development of PVC control strategies.