High-frequency thermoacoustic modulation mechanisms in swirl-stabilized gas turbine combustors part two: Modeling and analysis

Tobias Hummel, Frederik Berger, Michael Hertweck, Bruno Schuermans, Thomas Sattelmayer

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

9 Scopus citations

Abstract

This paper deals with high-frequency thermoacoustic instabilities in swirl-stabilized gas turbine combustors. Driving mechanisms associated with periodic flame displacement and flame shape deformations are theoretically discussed, and corresponding flame transfer functions are derived from first principles. These linear feedback models are then evaluated by means of a lab-scale swirl-stabilized combustor in combination with part one of this joint publication. For this purpose, the models are used to thermoacoustically characterize a complete set of operation points of a this combustor facility. Specifically, growth rates of the first transversal modes are computed, and compared against experimentally obtained pressure amplitudes as an indicator for thermoacoustic stability. The characterization is based on a hybrid analysis approach relying on a frequency domain formulation of acoustic conservation equations, in which non-uniform temperature fields and distributed thermoacoustic source terms/flame transfer functions can be straightforwardly considered. The relative contribution of flame displacement and deformation driving mechanisms - i.e. their significance with respect to the total driving - is identified. Furthermore, promoting/inhibiting conditions for the occurrence of high frequency, transversal acoustic instabilities within swirl-stabilized gas turbine combustors are revealed.

Original languageEnglish
Title of host publicationCombustion, Fuels and Emissions
PublisherAmerican Society of Mechanical Engineers (ASME)
ISBN (Electronic)9780791849767
DOIs
StatePublished - 2016
EventASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition, GT 2016 - Seoul, Korea, Republic of
Duration: 13 Jun 201617 Jun 2016

Publication series

NameProceedings of the ASME Turbo Expo
Volume4B-2016

Conference

ConferenceASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition, GT 2016
Country/TerritoryKorea, Republic of
CitySeoul
Period13/06/1617/06/16

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