Flame response mechanisms due to velocity perturbations in a lean premixed gas turbine combustor

Brian Jones, Jong Guen Lee, Bryan D. Quay, Domenic A. Santavicca, Kwanwoo Kim, Shiva Srinivasan

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

    4 Scopus citations

    Abstract

    The response of turbulent premixed flames to inlet velocity fluctuations is studied experimentally in a lean premixed, swirlstabilized, gas turbine combustor. Overall chemiluminescence intensity is used as a measure of the fluctuations in the flame's global heat release rate and hot wire anemometry is used to measure the inlet velocity fluctuations. Tests are conducted over a range of mean inlet velocities, equivalence ratios and velocity fluctuation frequencies, while the normalized inlet velocity fluctuation (V'/V mean) is fixed at 5% to ensure linear flame response over the employed modulation frequency range. The measurements are used to calculate a flame transfer function relating the velocity fluctuation to the heat release fluctuation as a function of the velocity fluctuation frequency. At low frequency, the gain of the flame transfer function increases with increasing frequency to a peak value greater than one. As the frequency is further increased, the gain decreases to a minimum value, followed by a second smaller peak. The frequencies at which the gain is minimum and achieves its 2 nd peak are found to depend on the convection time scale and the flame's characteristic length scale. Phasesynchronized CH* chemiluminescence imaging is used to characterize the flame's response to inlet velocity fluctuations. The observed flame response can be explained in terms of the interaction of two flame perturbation mechanisms, acoustic velocity fluctuations and vorticity fluctuations. Analysis of the phase-synchronized flame images show that when both perturbations arrive at the flame at the same time (or phase) they constructively interfere, producing the 2nd peak observed in the gain curves. And when the perturbations arrive at the flame 180 degrees out-of-phase, they destructively interfere, producing the observed minimum in the gain curve.

    Original languageEnglish (US)
    Title of host publicationASME Turbo Expo 2010
    Subtitle of host publicationPower for Land, Sea, and Air, GT 2010
    Pages323-333
    Number of pages11
    EditionPARTS A AND B
    DOIs
    StatePublished - Dec 1 2010
    EventASME Turbo Expo 2010: Power for Land, Sea, and Air, GT 2010 - Glasgow, United Kingdom
    Duration: Jun 14 2010Jun 18 2010

    Publication series

    NameProceedings of the ASME Turbo Expo
    NumberPARTS A AND B
    Volume2

    Other

    OtherASME Turbo Expo 2010: Power for Land, Sea, and Air, GT 2010
    CountryUnited Kingdom
    CityGlasgow
    Period6/14/106/18/10

    All Science Journal Classification (ASJC) codes

    • Engineering(all)

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