... Abstract Thermoacoustic instabilities have plagued the operation of gas turbine engines for years and significant research is being conducted in detecting and understanding them. In this paper, an output only identification technique is employed for a noise induced dynamical system representing...

... Abstract Thermoacoustic instabilities in annular or circular combustors are often coupled with azimuthal modes. These modes can be characterized by a spin ratio, which quantifies the dominant mode between two counter-rotating waves, and a phase difference between them, which is directly related...

... nitrogen oxide emissions, observed oscillating behavior of the spray characteristics. the major jet engine manufacturers are developing lean premixed prevaporized (LPP) combustors that operate at very Keywords: Atomization and sprays, Thermoacoustics, Jet high pressure. In this context, thermoacoustic...

...Abstract Abstract This paper analyzes the dynamics of unstable azimuthal thermoacoustic modes in a lean premixed combustor. Azimuthal modes can be decomposed into two counter rotating waves where they can either compete and potentially suppress one of them (spinning) or coexist (standing...

...Abstract Abstract Thermoacoustics (TA) engines and refrigerators typically run on the Stirling cycle with acoustic networks and resonators replacing the physical pistons. Without moving parts, these TA machines achieve a reasonable fraction of Carnot’s efficiency. They are also scalable, from...

... Proceedings of ASME Turbo Expo 2021 Turbomachinery Technical Conference and Exposition GT2021 June 7-11, 2021, Virtual, Online GT2021-59844 THERMOACOUSTIC BEHAVIOUR OF A HYDROGEN MICROMIX AVIATION GAS TURBINE COMBUSTOR UNDER TYPICAL FLIGHT CONDITIONS David Abbott*1, Alessandro Giannotta1, Xiaoxiao...

..., Tim Lieuwen1, Jim Blust2, Benjamin Emerson1 1Georgia Institute of Technology, Atlanta, GA 2Solar Turbines Incorporated, San Diego, CA ABSTRACT NOMENCLATURE Understanding thermoacoustic instabilities is essential for Bandwidth of data processing window the reliable operation of gas turbine engines...

... combustion systems can reduce NOx emissions from gas turbines, but un- fortunately also increases their susceptibility to thermoacoustic instabilities. Initially, acoustic waves can produce heat release fluctuations by a variety of mechanisms, often by perturbing the equivalence ratio. If correctly phased...

... 07 05 2012 Intense research on the thermoacoustic stability of premixed gas turbine combustors in the past two decades has led to an improved understanding of instabilities of longitudinal modes in the sub-kHz range and predictive tools for thermoacoustic stability analysis have also...

... for developing control strategies. Combustion Instabilities G-Equation Thermoacoustics Gas Turbines Premixed Flames Proceedings of The ASME Turbo Expo ASME2011 June 06-11, 2011, Vancouver, Canada GT2011-45255 LOW-ORDER MODELLING OF DUCTED FLAMES WITH TEMPORALLY VARYING EQUIVALENCE RATIO IN REALISTIC...

... because neither a dynamic sensor signal nor a signal processor is required. On the other hand, since the mechanism by which this type of con- trol suppresses an unstable thermoacoustic mode is inherently nonlinear, a comprehensive explanation for success (or failure) of open-loop control has not been...

... 04 08 2009 Evaluation of thermoacoustic properties of gas turbine combustion systems during the design phase is crucial to meet time to market requirements for advanced new gas turbines. During the design phase the impact of design changes on engine performance need to be assessed...

... 10 03 2009 In early design phases new burner concepts are mostly tested in single or multi burner test rigs. These test rigs generally exhibit a different acoustic behavior than the full scale engine. The acoustic behavior, however, is crucial to predict whether thermoacoustic...

... cooling were combined with a reduced chemical scheme that predicts NOx emissions. Good agreement of the calculated flame position and shape with experimental data was found. gas turbine combustor laser diagnostics thermoacoustics numerical simulation 1 Copyright © 2006 by ASME flame position...