Fuel-forced flame response of a lean-premixed combustor

Poravee Orawannukul, Jong Guen Lee, Bryan D. Quay, Domenic A. Santavicca

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    7 Scopus citations


    The response of a swirl-stabilized flame to equivalence ratio fluctuations is experimentally investigated in a single-nozzle lean premixed combustor. Equivalence ratio fluctuations are produced using a siren device to modulate the flow rate of fuel to the injector, while the air flow rate is kept constant. The magnitude and phase of the equivalence ratio fluctuations are measured near the exit of the nozzle using an infrared absorption technique. The flame response is characterized by the fluctuation in the flame's overall rate of heat release, which is determined from the total CH* chemiluminescence emission from the flame. The relationship between total CH* chemiluminescence intensity and the flame's overall rate of heat release is determined from a separate calibration experiment which accounts for the nonlinear relationship between chemiluminescence intensity and equivalence ratio. Measurements of the normalized equivalence ratio fluctuation and the normalized rate of heat release fluctuation are made over a range of modulation frequencies from 200 Hz to 440 Hz, which corresponds to Strouhal numbers from 0.4 to 2.8. These measurements are used to determine the fuel-forced flame transfer function which expresses the relationship between the equivalence ratio and rate of heat release fluctuations in terms of a gain and phase as a function of frequency. In addition, phase-synchronized CH* chemiluminescence images are captured to study the dynamics of the flame response over the modulation period. These measurements are made over a range of operating conditions and the results are analyzed to identify and better understand the mechanisms whereby equivalence ratio fluctuations result in fluctuations in the flame's overall rate of heat release. Such information is essential to guide the formulation and validation of analytical fuel-forced flame response models and hence to predict combustion dynamics in gas turbine combustors.

    Original languageEnglish (US)
    Title of host publicationASME 2011 Turbo Expo
    Subtitle of host publicationTurbine Technical Conference and Exposition, GT2011
    Number of pages12
    EditionPARTS A AND B
    StatePublished - 2011
    EventASME 2011 Turbo Expo: Turbine Technical Conference and Exposition, GT2011 - Vancouver, BC, Canada
    Duration: Jun 6 2011Jun 10 2011

    Publication series

    NameProceedings of the ASME Turbo Expo
    NumberPARTS A AND B


    OtherASME 2011 Turbo Expo: Turbine Technical Conference and Exposition, GT2011
    CityVancouver, BC

    All Science Journal Classification (ASJC) codes

    • General Engineering


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