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dc.contributor.authorKim, Jeongwon
dc.contributor.authorGillman, Wesley
dc.contributor.authorWu, David
dc.contributor.authorEmerson, Benjamin
dc.contributor.authorAcharya, Vishal
dc.contributor.authorMckinney, Randal
dc.contributor.authorIsono, Mitsunori
dc.contributor.authorSaitoh, Toshihiko
dc.contributor.authorLieuwen, Timothy C.
dc.date.accessioned2020-02-03T21:43:13Z
dc.date.available2020-02-03T21:43:13Z
dc.date.issued2020-01
dc.identifier.urihttp://hdl.handle.net/1853/62414
dc.descriptionPresented at the Georgia Tech Career, Research, and Innovation Development Conference (CRIDC), January 27-28, 2020, Georgia Tech Global Learning Center, Atlanta, GA.en_US
dc.descriptionThe Career, Research, and Innovation Development Conference (CRIDC) is designed to equip on-campus and online graduate students with tools and knowledge to thrive in an ever-changing job market.en_US
dc.description.abstractHigh frequency thermoacoustic instabilities are problematic for lean-premixed gas turbines. Identifying which acoustic mode is being excited is important, in that it provides insight into potential mitigation measures, as well as input into mechanical stress/lifing calculations. However, the frequency spacing between modes becomes significantly narrower for high frequency instabilities in a can combustor. This makes it difficult to distinguish between the modes (e.g., the first transverse mode vs. a higher order axial/mixed mode) based upon frequency calculations alone, which inevitably have uncertainties in boundary conditions, temperature profiles, and combustion response. This paper presents a methodology to simultaneously identify the acoustic mode shapes in the axial and azimuthal directions from acoustic pressure measurements. Multiple high temperature pressure transducers, located at distinct axial and azimuthal positions, are flush mounted in the combustor wall. The measured pressure oscillations from each sensor are then used to reconstruct the pressure distributions by using a least squares method in conjunction with a solution of a three dimensional wave equation. In order to validate the methodology, finite element method (FEM) with estimated post-flame temperature is used to provide the candidate frequencies and corresponding mode shapes. The results demonstrate the reconstructed mode shapes and standing/spinning character of transverse waves, as well as the associated frequencies, both of which are consistent with the FEM predictions. Nodal line location was also extracted from the experimental data during the instabilities in the pressure data. It was found that the line was wandering at fixed location for one mode, whereas the line was rotating in one direction for the other mode. This paper details these experimental measurements and analysis methodologies for high frequency modal identification in self-excited can combustors.en_US
dc.language.isoen_USen_US
dc.publisherGeorgia Institute of Technologyen_US
dc.relation.ispartofseriesCRIDCen_US
dc.subjectCombustionen_US
dc.subjectGas turbineen_US
dc.subjectThermoacousticen_US
dc.titleIdentification of High-Frequency Transverse Acoustic Modes In Multi-Nozzle Can Combustorsen_US
dc.typePosteren_US
dc.contributor.corporatenameGeorgia Institute of Technology. Center for Career Discovery and Developmenten_US
dc.contributor.corporatenameGeorgia Institute of Technology. Office of Graduate Studiesen_US
dc.contributor.corporatenameGeorgia Institute of Technology. Office of the Vice Provost for Graduate Education and Faculty Developmenten_US
dc.contributor.corporatenameGeorgia Institute of Technology. Student Government Associationen_US
dc.contributor.corporatenameGeorgia Institute of Technology. School of Mechanical Engineeringen_US


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