Journal ArticleDOI
Dynamics of Swirling Flames
TLDR
In this paper, 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, is presented, where the interaction between the swirler response and incoming acoustic perturbations generates a vorticity wave convected by the flow.Abstract:
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, howev...read more
Citations
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Journal ArticleDOI
Prediction and control of combustion instabilities in real engines
Thierry Poinsot,Thierry Poinsot +1 more
TL;DR: In this paper, the authors present recent progress in the field of thermoacoustic combustion instabilities in propulsion engines such as rockets or gas turbines, and show that LES is not sufficient and that theory, even in these complex systems, plays a major role to understand both experimental and LES results and to identify mitigation techniques.
Journal ArticleDOI
Transverse combustion instabilities: Acoustic, fluid mechanic, and flame processes
TL;DR: In this paper, the authors present a review of transverse acoustic wave motions in air-breathing systems and discuss issues associated with simulating or scaling instabilities, either in subscale experimental geometries or by attempting to understand instability physics using identical axial oscillations of the same frequency as the transverse mode of interest.
Journal ArticleDOI
Ammonia–methane combustion in tangential swirl burners for gas turbine power generation
Agustin Valera-Medina,Richard Marsh,Jon Runyon,Daniel Pugh,Paul Beasley,Timothy R. Hughes,Phil Bowen +6 more
TL;DR: In this paper, a generic tangential swirl burner has been employed to determine flame stability and emissions produced at different equivalence ratios using ammonia-methane blends, and it is concluded that a fully premixed injection strategy is not appropriate for optimised ammonia combustion and that high flame instabilities can be produced at medium swirl numbers, hence necessitating lower swirl and a different injection strategy for optimized power generation utilising ammonia fuel blends.
Journal ArticleDOI
Sensitivity and Nonlinearity of Thermoacoustic Oscillations
Matthew P. Juniper,R. I. Sujith +1 more
TL;DR: In this article, a review explains why linear and nonlinear thermoacoustic behavior is so sensitive to parameters such as operating point, fuel composition, and injector geometry, and proposes tools to exploit this sensitivity in the future: adjoint-based sensitivity analysis to optimize passive control designs and complex systems theory to warn of impending thermo-acoustic oscillations and to identify the most sensitive elements of a thermo acoustic system.
Journal ArticleDOI
Review of laboratory swirl burners and experiments for model validation
TL;DR: In this article, an overview of the literature on laboratory-scale swirl flame burners is presented, focusing on selected gaseous fuel burners that span premixed, partially premixed and non-premixed combustion over unconfined and confined conditions.
References
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Book
Stability and Transition in Shear Flows
TL;DR: In this article, the authors present an approach to the Viscous Initial Value Problem with the objective of finding the optimal growth rate and the optimal response to the initial value problem.
Journal ArticleDOI
Local and global instabilities in spatially developing flows
TL;DR: In this article, a review of recent developments in the hydro- dynamic stability theory of spatially developing flows pertaining to absolute/convective and local/global instability concepts is presented.
Journal ArticleDOI
Dynamics and stability of lean-premixed swirl-stabilized combustion
Ying Huang,Vigor Yang +1 more
TL;DR: A comprehensive review of the advances made over the past two decades in this area is provided in this article, where various swirl injector configurations and related flow characteristics, including vortex breakdown, precessing vortex core, large-scale coherent structures, and liquid fuel atomization and spray formation are discussed.
BookDOI
Combustion Instabilities In Gas Turbine Engines: Operational Experience, Fundamental Mechanisms, and Modeling
Tim Lieuwen,Vigor Yang +1 more
TL;DR: In this paper, the authors compile these results into a series of chapters that address the various facets of the combustion instabilities in low-emission gas turbines and provide a valuable resource to help turbine users and manufacturers.
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Combustion Instabilities In Gas Turbine Engines: Operational Experience, Fundamental Mechanisms, and Modeling
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