Analysis of Hydrodynamic Instabilities and Combustion Dynamics in Turbulent Reacting Flows.

Large Eddy Simulation;Combustion;Linear Stability Analysis;Flamelet;Aerospace Engineering;Engineering;Aerospace Engineering

See, Yee CheeHultgren, Lennart S. ;

University of Michigan

关键词: Large Eddy Simulation;    Combustion;    Linear Stability Analysis;    Flamelet;    Aerospace Engineering;    Engineering;    Aerospace Engineering;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/107148/seeyc_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

The design of new gas turbine engine combustors is largelydriven by the demand for higher fuel efficiencies andincreasingly stringent emission regulations. Predictivemodeling capabilities can assist in the design-process of suchadvanced combustion systems. These modeling capabilities can generally becategorized into low-order and high-fidelity approaches.This work considers both approaches to model,analyze, and characterize hydrodynamic and combustion-driveninstabilities in turbulent reacting flows. Severalmodel-developments are performed in order to improvethe physical representation of low-order models, therebyenabling a consistent representation of fundamentalcombustion-physical processes, including thereaction-chemistry, the thermo-viscous-diffusive transport,and the combustion representation. The resultingmodel-formulation is demonstrated in application to linear stability analysis of a jet-diffusion flame.Comparisons with experimental data and detailed simulation resultsare performed, and fundamental physical processes, relatedto the coupling of buoyancy, transport-properties, and therepresentation of the reaction chemistry, are analyzed. Thesecond part of this work addresses the high-fidelitymodeling, and large-eddy simulations of a dual-swirlgas-turbine model combustor are performed. A comprehensivemodel-analysis is conducted to systematically investigatethe influence of mesh-resolution, subgrid-models,boundary-conditions, and closure-formulations on theflow-field structure and flame-shape. A prior modelexamination is performed to assess the role of thecombustion-regime representation, and it is found thatpremixed and non-premixed combustion-models providecomparable results. Comprehensive comparisons withexperimental data are performed and it is shown that thecombustion models accurately capture the complex combustiondynamics present in this burner. Effects ofheat-losses and the representation of flame-wrinkling at theresidual scales on the flow-field structure are analyzed,and limitations of these combustion models are examined.