Abstract
Abstract : A concurrent computational and experimental study of self-excited combustion dynamics in a model configuration of a lean direct injection (LDI) gas turbine combustor is described. Incoming air temperature and equivalence ratio were varied. Simulation at low equivalence ratio compared better with measurement and thus this condition was selected for a more detailed study of the underlying combustion dynamics mechanisms. First, hydrodynamic modes are investigated by conducting the simulation with an acoustically-open combustor so that acoustic effects on the flow field are minimized. The Vortex Breakdown Bubble (VBB) proves to be an important flow structure that can easily interact with the acoustic field to sustain instability. Second, detailed cycle studies of the acoustically closed combustor simulation reveals enhanced mixing and vaporization of the JP-8 fuel spray due to acoustic compression wave. Dynamic Mode Decomposition (DMD) analysis is used to identify the coupling between axial acoustics and the vortex breakdown bubble in the lower frequency region. Presence of another important hydrodynamic mode, the Precessing Vortex Core (PVC) is also identified from the DMD analysis. The possibility of nonlinear coupling between the acoustics and PVC modes is indicated.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
