Cinematographic OH-PLIF measurements of two interacting turbulent premixed flames with and without acoustic forcing

Worth, Nicholas A.; Dawson, James

doi:10.1016/j.combustflame.2011.09.006

Cited by 77 publications

(45 citation statements)

References 36 publications

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“…In multiburner annular chambers, the stabilization of swirling flames often differs from that observed for similar operating conditions in a single-burner configuration www.annualreviews.org • Dynamics of Swirling Flames (Fanaca et al 2010). In these multi-injection systems, the response of a burner to flow perturbations may then be altered by the presence of neighboring flames (Worth & Dawson 2012), and the dynamics of azimuthal unstable modes in annular geometries is in turn modified (Worth & Dawson 2013, Bourgouin et al 2013b. Recent simulations (Boileau et al 2008) and experiments (Bourgouin et al 2013a) in annular geometries also revealed the complex light-around dynamics taking place in the chamber, emphasizing different interactions with the flame for injectors located clockwise or counterclockwise with the swirling flow.…”

Section: Other Types Of Swirling Flamesmentioning

confidence: 95%

Dynamics of Swirling Flames

Candel

Durox²,

Schuller³

et al. 2014

Annu. Rev. Fluid Mech.

370

157

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In many continuous combustion processes, such as those found in aeroengines or gas turbines, the flame is stabilized by a swirling flow formed by aerodynamic swirlers. The dynamics of such swirling flames is of technical and fundamental interest. This article reviews progress in this field and begins with a discussion of the swirl number, a parameter that plays a central role in the definition of the flow structure and its response to incoming disturbances. Interaction between the swirler response and incoming acoustic perturbations generates a vorticity wave convected by the flow, which is accompanied by azimuthal velocity fluctuations. Axial and azimuthal velocities in turn define the flame response in terms of heat release rate fluctuations. The nonlinear response of swirling flames to incoming disturbances is conveniently represented with a flame describing function (FDF), in other words, with a family of transfer functions depending on frequency and incident axial velocity amplitudes. The FDF, however, does not reflect all possible nonlinear interactions in swirling flows. This aspect is illustrated with experimental data and some theoretical arguments in the last part of this article, which concerns the interaction of incident acoustic disturbances with the precessing vortex core, giving rise to nonlinear fluctuations at the frequency difference.

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Section: Other Types Of Swirling Flamesmentioning

confidence: 95%

Dynamics of Swirling Flames

Candel

Durox²,

Schuller³

et al. 2014

Annu. Rev. Fluid Mech.

370

157

View full text Add to dashboard Cite

show abstract

“…The experimental characterization of transversely excited swirled jets has been presented earlier by O'Connor and co-workers [14][15][16], Hauser et al [17], and Worth and Dawson [18,19] for the low-frequency range. High-frequency instabilities in swirlstabilised flames were observed in the numerical works of Huang et al [20,21] and Huang and Yang [22], who gave a detailed description of the flame dynamics using proper orthogonal decomposition (POD) methods.…”

Section: Introductionmentioning

confidence: 95%

Experimental and Numerical Investigation of Thermoacoustic Sources Related to High-Frequency Instabilities

Zellhuber

Schwing

Schuermans

et al. 2014

International Journal of Spray and Combustion Dynamics

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Flame dynamics related to high-frequency instabilities in gas turbine combustors are investigated using experimental observations and numerical simulations. Two different combustor types are studied, a premix swirl combustor (experiment) and a generic reheat combustor (simulation). In both cases, a very similar dynamic behaviour of the reaction zone is observed, with the appearance of transverse displacement and coherent flame wrinkling. From these observations, a model for the thermoacoustic feedback linked to transverse modes is proposed. The model splits heat release rate fluctuations into distinct contributions that are related to flame displacement and variations of the mass burning rate. The decomposition procedure is applied on the numerical data and successfully verified by comparing a reconstructed Rayleigh index with the directly computed value. It thus allows to quantify the relative importance of various feedback mechanisms for a given setup.

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“…Those measurements include OH* and CH* chemiluminescence to identify heat release variations, OH, CH 2 O and CH PLIF to determine fluctuations in the flame surface density or local Rayleigh index and laser Raman measurements to assess changes in the thermo-chemical state of the flame [Bellows 2007, Biagioli 2008, Giezendanner 2003, Hubschmid 2008, Ishino 2001, Lee 2003, Schildmacher 2006. More recently, high-speed imaging techniques in combination with acoustic pressure tracing have been applied to study thermo-acoustic instabilities in GT-relevant combustors , Caux-Brisebois 2014, Durox 2013, Galley 2011, Gounder 2014, Steinberg 2010, Steinberg 2012, Steinberg 2013, Worth 2012, yielding deeper insight into the feedback mechanisms.…”

Section: Introductionmentioning

confidence: 99%