Development and validation of a framework to predict the linear stability of transverse thermoacoustic modes of a reheat combustor

Uložené v:
Podrobná bibliografia
Názov: Development and validation of a framework to predict the linear stability of transverse thermoacoustic modes of a reheat combustor
Autori: Heinzmann, Simon M., Gopalakrishnan, Harish S., Gant, Francesco, Bothien, Mirko R.
Zdroj: Combustion and Flame, 275
Combustion and Flame
Informácie o vydavateľovi: Elsevier BV, 2025.
Rok vydania: 2025
Predmety: FEM, Transverse modes, Thermoacoustics, Auto-ignition flame, Eigenmode, Stability analysis, Transverse mode, 620: Ingenieurwesen
Popis: To achieve fully carbon-neutral, fuel-flexible and on-demand grid power delivery, gas turbines featuring constant pressure sequential combustion architecture show great potential. A sequential combustor is comprised of two axially-staged combustion chambers with the first stage typically being a swirl-stabilised propagating flame. Post first stage combustion, the exhaust stream is first diluted with air and later enriched with additional fuel in the second stage resulting in a vitiated product mixture at high temperatures leading to auto-ignition. Thermoacoustically-stable combustion stages are critical to ensure low emissions, high reliability and ensure mechanical integrity. The second stage firing under auto-ignition conditions can be subject to transversal instabilities. This article presents a finite element coupled method to model the thermoacoustic behaviour of a second stage reheat flame in an efficient, cost-effective approach. To do so, prior techniques to model the response of autoignition-stabilised flames to longitudinal acoustic perturbations is leveraged to quantify the auto-ignition flame's heat release rate response to transverse acoustic waves. Subsequently, the framework is used to compute the stability of transverse eigenmodes for an atmospheric reheat combustor. Validation is performed by comparison to experimentally obtained pressure sensor measurements and chemiluminescence imaging of the flame. It is observed that the framework can correctly predict the combustor's unstable first transverse mode and also capture the dynamic flame response qualitatively. Consequently, the framework presented in this work can be leveraged to get reliable and time-efficient stability estimates of the transverse thermoacoustic modes in experimental reheat burners.
Combustion and Flame, 275
ISSN:0010-2180
ISSN:1556-2921
Druh dokumentu: Article
Popis súboru: application/application/pdf
Jazyk: English
ISSN: 0010-2180
DOI: 10.1016/j.combustflame.2025.114010
DOI: 10.3929/ethz-b-000723733
DOI: 10.21256/zhaw-32420
Prístupová URL adresa: http://hdl.handle.net/20.500.11850/723733
Rights: CC BY
Elsevier TDM
Prístupové číslo: edsair.doi.dedup.....55ec1c2e8f31a25831c70a2c60812099
Databáza: OpenAIRE
Popis
Abstrakt:To achieve fully carbon-neutral, fuel-flexible and on-demand grid power delivery, gas turbines featuring constant pressure sequential combustion architecture show great potential. A sequential combustor is comprised of two axially-staged combustion chambers with the first stage typically being a swirl-stabilised propagating flame. Post first stage combustion, the exhaust stream is first diluted with air and later enriched with additional fuel in the second stage resulting in a vitiated product mixture at high temperatures leading to auto-ignition. Thermoacoustically-stable combustion stages are critical to ensure low emissions, high reliability and ensure mechanical integrity. The second stage firing under auto-ignition conditions can be subject to transversal instabilities. This article presents a finite element coupled method to model the thermoacoustic behaviour of a second stage reheat flame in an efficient, cost-effective approach. To do so, prior techniques to model the response of autoignition-stabilised flames to longitudinal acoustic perturbations is leveraged to quantify the auto-ignition flame's heat release rate response to transverse acoustic waves. Subsequently, the framework is used to compute the stability of transverse eigenmodes for an atmospheric reheat combustor. Validation is performed by comparison to experimentally obtained pressure sensor measurements and chemiluminescence imaging of the flame. It is observed that the framework can correctly predict the combustor's unstable first transverse mode and also capture the dynamic flame response qualitatively. Consequently, the framework presented in this work can be leveraged to get reliable and time-efficient stability estimates of the transverse thermoacoustic modes in experimental reheat burners.<br />Combustion and Flame, 275<br />ISSN:0010-2180<br />ISSN:1556-2921
ISSN:00102180
DOI:10.1016/j.combustflame.2025.114010