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Title: Spatially distributed flame transfer functions for predicting combustion dynamics in lean premixed gas turbine combustors

The present paper describes a methodology to improve the accuracy of prediction of the eigenfrequencies and growth rates of self-induced instabilities and demonstrates its application to a laboratory-scale, swirl-stabilized, lean-premixed, gas turbine combustor. The influence of the spatial heat release distribution is accounted for using local flame transfer function (FTF) measurements. The two-microphone technique and CH{sup *} chemiluminescence intensity measurements are used to determine the input (inlet velocity perturbation) and the output functions (heat release oscillation), respectively, for the local flame transfer functions. The experimentally determined local flame transfer functions are superposed using the flame transfer function superposition principle, and the result is incorporated into an analytic thermoacoustic model, in order to predict the linear stability characteristics of a given system. Results show that when the flame length is not acoustically compact the model prediction calculated using the local flame transfer functions is better than the prediction made using the global flame transfer function. In the case of a flame in the compact flame regime, accurate predictions of eigenfrequencies and growth rates can be obtained using the global flame transfer function. It was also found that the general response characteristics of the local FTF (gain and phase) are qualitatively themore » same as those of the global FTF. (author)« less
Authors:
; ; ;  [1]
  1. Center for Advanced Power Generation, Department of Mechanical and Nuclear Engineering, Pennsylvania State University, University Park, PA (United States)
Publication Date:
OSTI Identifier:
21337868
Resource Type:
Journal Article
Resource Relation:
Journal Name: Combustion and Flame; Journal Volume: 157; Journal Issue: 9; Other Information: Elsevier Ltd. All rights reserved
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; TRANSFER FUNCTIONS; GAS TURBINES; FLAMES; COMBUSTION; HEAT; COMBUSTION INSTABILITY; FORECASTING; EIGENFREQUENCY; COMBUSTORS; DISTRIBUTION; GAIN; ACCURACY; DISTURBANCES; OSCILLATIONS; STABILITY; VELOCITY; INSTABILITY GROWTH RATES Flame transfer functions; Heat release distribution