Analytical and experimental investigation of frequency of oscillation modes in combustion chambers of gas turbines

• Published in: Proceedings of the Institution of Mechanical Engineers. Part G, Journal of aerospace engineering Vol. 223; no. 6; pp. 741 - 747
• Main Authors: Akbari, N, Seraj Mehdizadeh, N, Ebrahimi, R
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.09.2009; SAGE PUBLICATIONS, INC
• Subjects: Acoustic instability; Combustion; Combustion chambers; Computer programs; Computer simulation; Emission spectra; Emissions; Flue gas; Fluidized bed combustion; Gas turbine engines; Gas turbines; Histograms; Instability; Jets; Mathematical analysis; Nitrogen oxides; Oscillation modes; Stability; Stability analysis; Turbines; premixed combustion; combustion instability; thermo-acoustic instability; gas turbines
• ISSN: 0954-4100; 2041-3025
• DOI: 10.1243/09544100JAERO468

Abstract Premixed combustion is widely used for simulation of combustion chambers of gas turbines, utilized for low NO x emission applications. However, this category of gas turbines is susceptible to combustion instability. Combustion instability has already been studied for industrial burners, ram jets, and pulse jets. But, with regard to modern gas turbines, there are limited works that are performed recently. Therefore, the main aim of this investigation is focused on thermo-acoustic instability modes in gas turbine combustion chambers. Both analytical and experimental methods are applied for this study. For this purpose, an experimental combustion chamber is designed and fabricated and various experiments are planned and performed in order to achieve the behaviour of combustion chamber during stable and unstable conditions. Moreover, an analytical method is applied and a computer code is written and elaborated for this purpose. Instability frequencies are derived experimentally and analytically and the results are compared with each other. Accordingly, good agreements are observed between the results. In addition, histograms, spectral diagrams, and wave forms of thermo-acoustic instability are achieved experimentally.