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

    Research output: Contribution to journalArticle

    29 Citations (Scopus)

    Abstract

    The response of turbulent premixed flames to inlet velocity fluctuations is studied experimentally in a lean premixed, swirl-stabilized, 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 1. 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 second peak are found to depend on the convection time scale and the flame's characteristic length scale. Phase-synchronized 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, one originating at flame-anchoring point and propagating along the flame front and the other from vorticity field generated in the outer shear layer in the annular mixing section. An 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 second peak observed in the gain curves. 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)
    Article number021503
    JournalJournal of Engineering for Gas Turbines and Power
    Volume133
    Issue number2
    DOIs
    StatePublished - Jan 1 2011

    Fingerprint

    Combustors
    Gas turbines
    Chemiluminescence
    Transfer functions
    Frequency modulation
    Vorticity
    Wire
    Imaging techniques

    All Science Journal Classification (ASJC) codes

    • Nuclear Energy and Engineering
    • Fuel Technology
    • Aerospace Engineering
    • Energy Engineering and Power Technology
    • Mechanical Engineering

    Cite this

    Jones, Brian ; Lee, Jong Guen ; Quay, Bryan D. ; Santavicca, Domenic A. / Flame response mechanisms due to velocity perturbations in a lean premixed gas turbine combustor. In: Journal of Engineering for Gas Turbines and Power. 2011 ; Vol. 133, No. 2.
    @article{1daca221a1bf49a3b510ada1ac107d07,
    title = "Flame response mechanisms due to velocity perturbations in a lean premixed gas turbine combustor",
    abstract = "The response of turbulent premixed flames to inlet velocity fluctuations is studied experimentally in a lean premixed, swirl-stabilized, 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 1. 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 second peak are found to depend on the convection time scale and the flame's characteristic length scale. Phase-synchronized 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, one originating at flame-anchoring point and propagating along the flame front and the other from vorticity field generated in the outer shear layer in the annular mixing section. An 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 second peak observed in the gain curves. When the perturbations arrive at the flame 180 degrees out-of-phase, they destructively interfere, producing the observed minimum in the gain curve.",
    author = "Brian Jones and Lee, {Jong Guen} and Quay, {Bryan D.} and Santavicca, {Domenic A.}",
    year = "2011",
    month = "1",
    day = "1",
    doi = "10.1115/1.4001996",
    language = "English (US)",
    volume = "133",
    journal = "Journal of Engineering for Gas Turbines and Power",
    issn = "0742-4795",
    publisher = "American Society of Mechanical Engineers(ASME)",
    number = "2",

    }

    Flame response mechanisms due to velocity perturbations in a lean premixed gas turbine combustor. / Jones, Brian; Lee, Jong Guen; Quay, Bryan D.; Santavicca, Domenic A.

    In: Journal of Engineering for Gas Turbines and Power, Vol. 133, No. 2, 021503, 01.01.2011.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Flame response mechanisms due to velocity perturbations in a lean premixed gas turbine combustor

    AU - Jones, Brian

    AU - Lee, Jong Guen

    AU - Quay, Bryan D.

    AU - Santavicca, Domenic A.

    PY - 2011/1/1

    Y1 - 2011/1/1

    N2 - The response of turbulent premixed flames to inlet velocity fluctuations is studied experimentally in a lean premixed, swirl-stabilized, 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 1. 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 second peak are found to depend on the convection time scale and the flame's characteristic length scale. Phase-synchronized 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, one originating at flame-anchoring point and propagating along the flame front and the other from vorticity field generated in the outer shear layer in the annular mixing section. An 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 second peak observed in the gain curves. When the perturbations arrive at the flame 180 degrees out-of-phase, they destructively interfere, producing the observed minimum in the gain curve.

    AB - The response of turbulent premixed flames to inlet velocity fluctuations is studied experimentally in a lean premixed, swirl-stabilized, 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 1. 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 second peak are found to depend on the convection time scale and the flame's characteristic length scale. Phase-synchronized 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, one originating at flame-anchoring point and propagating along the flame front and the other from vorticity field generated in the outer shear layer in the annular mixing section. An 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 second peak observed in the gain curves. When the perturbations arrive at the flame 180 degrees out-of-phase, they destructively interfere, producing the observed minimum in the gain curve.

    UR - http://www.scopus.com/inward/record.url?scp=78649305584&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=78649305584&partnerID=8YFLogxK

    U2 - 10.1115/1.4001996

    DO - 10.1115/1.4001996

    M3 - Article

    AN - SCOPUS:78649305584

    VL - 133

    JO - Journal of Engineering for Gas Turbines and Power

    JF - Journal of Engineering for Gas Turbines and Power

    SN - 0742-4795

    IS - 2

    M1 - 021503

    ER -