Effect of Flame Structure on the Flame Transfer Function in a Premixed Gas Turbine Combustor
- 16 October 2009
- journal article
- Published by ASME International in Journal of Engineering for Gas Turbines and Power
- Vol. 132 (2), 021502
- https://doi.org/10.1115/1.3124664
Abstract
The flame transfer function in a premixed gas turbine combustor is experimentally determined. The fuel (natural gas) is premixed with air upstream of a choked inlet to the combustor. Therefore, the input to the flame transfer function is the imposed velocity fluctuations of the fuel/air mixture without equivalence ratio fluctuations. The inlet-velocity fluctuations are achieved by a variable-speed siren over the forcing frequency of 75–280 Hz and measured using a hot-wire anemometer at the inlet to the combustor. The output function (heat release) is determined using chemiluminescence measurement from the whole flame. Flame images are recorded to understand how the flame structure plays a role in the global heat release response of flame to the inlet-velocity perturbation. The results show that the gain and phase of the flame transfer function depend on flame structure as well as the frequency and magnitude of inlet-velocity modulation and can be generalized in terms of the relative length scale of flame to convection length scale of inlet-velocity perturbation, which is represented by a Strouhal number. Nonlinear flame response is characterized by a periodic vortex shedding from shear layer, and the nonlinearity occurs at lower magnitude of inlet-velocity fluctuation as the modulation frequency increases. However, for a given modulation frequency, the flame structure does not affect the magnitude of inlet-velocity fluctuation at which the nonlinear flame response starts to appear.Keywords
This publication has 16 references indexed in Scilit:
- LES and experimental studies of cold and reacting flow in a swirled partially premixed burner with and without fuel modulationCombustion and Flame, 2007
- Dynamics of confined premixed flames submitted to upstream acoustic modulationsProceedings of the Combustion Institute, 2007
- Nonlinear Flame Transfer Function Characteristics in a Swirl-Stabilized CombustorJournal of Engineering for Gas Turbines and Power, 2006
- Investigation of the nonlinear response of turbulent premixed flames to imposed inlet velocity oscillationsCombustion and Flame, 2006
- Experimental investigation of the nonlinear response of turbulent premixed flames to imposed inlet velocity oscillationsCombustion and Flame, 2005
- Modeling Premixed Combustion-Acoustic Wave Interactions: A ReviewJournal of Propulsion and Power, 2003
- Combustion dynamics of turbulent swirling flamesCombustion and Flame, 2002
- A kinematic model of a ducted flameJournal of Fluid Mechanics, 1999
- Thermoacoustic oscillations in combustion chambers of gas turbinesAIAA Journal, 1995
- Combustion instabilities coupled by pressure waves and their active controlSymposium (International) on Combustion, 1992