Flame leading edge and flow dynamics in a swirling, lifted flame

Michael Malanoski, Michael Aguilar, Jacqueline Antonia O'Connor, Dong Hyuk Shin, Bobby Noble, Tim Lieuwen

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

    7 Scopus citations

    Abstract

    Flames in high swirl flow fields with vortex breakdown often stabilize aerodynamically in front of interior flow stagnation points. In contrast to shear layer stabilized flames with a nearly fixed, well defined flame attachment point, the leading edge of aerodynamically stabilized flames can move around substantially, due to both the inherent dynamics of the vortex breakdown region, as well as externally imposed oscillations. Motion of this flame stabilization point relative to the flow field has an important dynamical role during combustion instabilities, as it creates flame front wrinkles and heat release fluctuations. For example, a prior study has shown that nonlinear dynamics of the flame response at high forcing amplitudes were related to these leading edge dynamics. This heat release mechanism exists alongside other flame wrinkling processes, arising from such processes as shear layer rollup and swirl fluctuations. This paper describes an experimental investigation of acoustic forcing effects on the dynamics of leading edge of a swirl stabilized flame. Vortex breakdown bubble dynamics were characterized using both high-speed particle image velocimetry (PIV) and line-of-sight high-speed CH* chemiluminescence. A wide array of forcing conditions was achieved by varying forcing frequency, amplitude, and acoustic field symmetry. These results show significant differences in instantaneous and time averaged location of the flow stagnation points. They also show motion of the flame leading edge that are of the same order of magnitude as corresponding particle displacement associated with the fluctuating velocity field. This observation suggests that heat release fluctuations associated with leading edge motion may be just as significant in controlling the unsteady flame response as the flame wrinkles excited by velocity fluctuations.

    Original languageEnglish (US)
    Title of host publicationASME Turbo Expo 2012
    Subtitle of host publicationTurbine Technical Conference and Exposition, GT 2012
    Pages199-209
    Number of pages11
    EditionPARTS A AND B
    DOIs
    StatePublished - Dec 1 2012
    EventASME Turbo Expo 2012: Turbine Technical Conference and Exposition, GT 2012 - Copenhagen, Denmark
    Duration: Jun 11 2012Jun 15 2012

    Publication series

    NameProceedings of the ASME Turbo Expo
    NumberPARTS A AND B
    Volume2

    Other

    OtherASME Turbo Expo 2012: Turbine Technical Conference and Exposition, GT 2012
    CountryDenmark
    CityCopenhagen
    Period6/11/126/15/12

    All Science Journal Classification (ASJC) codes

    • Engineering(all)

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  • Cite this

    Malanoski, M., Aguilar, M., O'Connor, J. A., Shin, D. H., Noble, B., & Lieuwen, T. (2012). Flame leading edge and flow dynamics in a swirling, lifted flame. In ASME Turbo Expo 2012: Turbine Technical Conference and Exposition, GT 2012 (PARTS A AND B ed., pp. 199-209). (Proceedings of the ASME Turbo Expo; Vol. 2, No. PARTS A AND B). https://doi.org/10.1115/GT2012-68256