Combustion instability is a serious problem limiting the operating envelope of present day gas turbine systems using a lean premixed combustion strategy. Gas turbine combustors employ swirl as a means for achieving fuel-air mixing as well as flame stabilization. However swirl flows are complex flows comprised of multiple shear layers as well as recirculation zones which makes them particularly susceptible to hydrodynamic instability. We perform a local stability analysis on a family of base flow model profiles characteristic of swirling flow that has undergone vortex breakdown as would be the case in a gas turbine combustor. A temporal analysis at azimuthal wavenumbers m = 0 and m = 1 reveals the presence of two unstable modes. A companion spatio-temporal analysis shows that the region in base flow parameter space for constant density density flow, over which m = 1 mode with the lower oscillation frequency is absolutely unstable, is much larger that that for the corresponding m = 0 mode. This suggests that the dominant self-excited unstable behavior in a constant density flow is an asymmetric, m=1 mode. The presence of a density gradient within the inner shear layer of the flow profile causes the absolutely unstable region for the m = 1 to shrink which suggests a possible explanation for the suppression of the precessing vortex core in the presence of a flame.
Skip Nav Destination
ASME Turbo Expo 2015: Turbine Technical Conference and Exposition
June 15–19, 2015
Montreal, Quebec, Canada
Conference Sponsors:
- International Gas Turbine Institute
ISBN:
978-0-7918-5668-0
PROCEEDINGS PAPER
Instability Mechanism in a Swirl Flow Combustor: Precession of Vortex Core and Influence of Density Gradient
Kiran Manoharan,
Kiran Manoharan
Indian Institute of Science, Bangalore, India
Search for other works by this author on:
Samuel Hansford,
Samuel Hansford
Pennsylvania State University, University Park, PA
Search for other works by this author on:
Jacqueline O’ Connor,
Jacqueline O’ Connor
Pennsylvania State University, University Park, PA
Search for other works by this author on:
Santosh Hemchandra
Santosh Hemchandra
Indian Institute of Science, Bangalore, India
Search for other works by this author on:
Kiran Manoharan
Indian Institute of Science, Bangalore, India
Samuel Hansford
Pennsylvania State University, University Park, PA
Jacqueline O’ Connor
Pennsylvania State University, University Park, PA
Santosh Hemchandra
Indian Institute of Science, Bangalore, India
Paper No:
GT2015-42985, V04AT04A073; 12 pages
Published Online:
August 12, 2015
Citation
Manoharan, K, Hansford, S, O’ Connor, J, & Hemchandra, S. "Instability Mechanism in a Swirl Flow Combustor: Precession of Vortex Core and Influence of Density Gradient." Proceedings of the ASME Turbo Expo 2015: Turbine Technical Conference and Exposition. Volume 4A: Combustion, Fuels and Emissions. Montreal, Quebec, Canada. June 15–19, 2015. V04AT04A073. ASME. https://doi.org/10.1115/GT2015-42985
Download citation file:
100
Views
0
Citations
Related Proceedings Papers
Related Articles
Combustion Instabilities and Control of a Multiswirl Atmospheric Combustor
J. Eng. Gas Turbines Power (January,2007)
Effect of Fuel System Impedance Mismatch on Combustion Dynamics
J. Eng. Gas Turbines Power (January,2008)
Optimization of the Aerodynamic Flame Stabilization for Fuel Flexible Gas Turbine Premix Burners
J. Eng. Gas Turbines Power (October,2011)
Related Chapters
Outlook
Closed-Cycle Gas Turbines: Operating Experience and Future Potential
The Identification of the Flame Combustion Stability by Combining Principal Component Analysis and BP Neural Network Techniques
International Conference on Mechanical Engineering and Technology (ICMET-London 2011)
Combined Cycle Power Plant
Energy and Power Generation Handbook: Established and Emerging Technologies