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PhD Proposal by Mitchell Passarelli

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Mitchell Passarelli
(Advisor: Prof. Adam Steinberg]

will propose a doctoral thesis entitled,

The Influence of Frequency Interactions on Flame Describing Functions for Pressurized Gas Turbine Combustors

On

Thursday May 12, 2022 at 10:00 a.m.-12:00 p.m.
Ben T. Zinn Combustion Lab Conference Room

https://teams.microsoft.com/l/meetup-join/19%3ameeting_YWQ0MGVlNmItYzAxNi00NTZiLTliNTMtMjc3YmUyNGY1NjQ0%40thread.v2/0?context=%7b%22Tid%22%3a%22482198bb-ae7b-4b25-8b7a-6d7f32faa083%22%2c%22Oid%22%3a%228cfa512f-befb-4184-b498-38b29cb41a0c%22%7d

Abstract

The main goal of research on combustion dynamics is to understand their origins, driving mechanisms and develop a robust and accurate method of predicting them in practical gas turbine combustors. The interactions between self-excited oscillations at different frequencies and related synchronization phenomena are of growing interest and recent studies demonstrate their effects are not negligible at flight-relevant operating conditions. From a modelling perspective, cross-frequency interactions and synchronization can alter the response of a system to perturbations in ways that confound existing models. From a control paradigm, synchronization can enable engine designers to tune dynamics away from problematic system states. Although these effects have yet to be fully quantified against existing modelling tools, the theoretical descriptions of synchronization within nonlinear dynamical systems theory provide a powerful framework for this task. The goal of the proposed research is to explore the specific ways that frequency interactions manifest and alter the response of combustor dynamics. To accomplish this goal, this research proposes analyzing the response of a combustor subjected to forcing at various frequencies and amplitudes. The response will be quantified via empirical, time-resolved measurements of the hydrodynamic and thermoacoustic behaviours. Stereoscopic particle image velocimetry (SPIV), OH* chemiluminescence (CL) and dynamic pressure transducers will measure the velocity, heat release rate and pressure fluctuations, respectively, within the combustor. Previous work on a swirl-stabilized flame in a model aeronautical gas turbine combustor at GE Research investigated the interactions of the natural dynamics with applied external forcing. The results of this work demonstrated some of the differences between not only the expectations informed by a linear stability analysis and experimental measurements, but also the interactions of various flow quantities subjected to the same forcing. The preliminary results are limited to qualitative comparisons with existing theory and models. Thus, the proposed work aims to collect data that can be used for quantitative analysis of these differences.

Committee

  • Prof. Adam Steinberg – School of Aerospace Engineering (advisor)
  • Prof. Tim Lieuwen – School of Aerospace Engineering
  • Prof. Jerry Seitzman – School of Aerospace Engineering

Status

  • Workflow Status:Published
  • Created By:Tatianna Richardson
  • Created:04/28/2022
  • Modified By:Tatianna Richardson
  • Modified:04/28/2022

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