CFD Modelling of Swirled-Stabilized Gas Turbine Burner with Mixture Stratification and Low Carbon Fuels
[EN] Aeronautical gas turbine engines are responsible for a significant part of energy consumption, pollution, and greenhouse gas emissions. As their demand has exponentially increased over the years, looking for alternative fuels to Jet-A1 to decarbonize the sector has become necessary. In the shor...
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| Tipo de recurso: | tesis de maestría |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universitat Politècnica de València (UPV) |
| Repositorio: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Idioma: | inglés |
| OAI Identifier: | oai:riunet.upv.es:10251/226752 |
| Acceso en línea: | https://riunet.upv.es/handle/10251/226752 |
| Access Level: | acceso abierto |
| Palabra clave: | CFD Metano Flujo con swirl Amoniaco-hidrógeno Turbina de gas Combustión Methane Swirling flow Ammonia-hydrogen Gas turbine Combustion Motores de turbina de gas Dinámica de Fluidos Computacional (CFD) Combustión amoníaco-hidrógeno Simulación LES (Large Eddy Simulation) Gas turbine engines Computational Fluid Dynamics (CFD) Ammonia-hydrogen combustion Large Eddy Simulation (LES) Máster Universitario en Mecánica de Fluidos Computacional-Màster Universitari en Mecànica de Fluids Computacional |
| Sumario: | [EN] Aeronautical gas turbine engines are responsible for a significant part of energy consumption, pollution, and greenhouse gas emissions. As their demand has exponentially increased over the years, looking for alternative fuels to Jet-A1 to decarbonize the sector has become necessary. In the short to medium term, the best option is to research the viability of low-carbon fuels such as synthetic methane and Sustainable Aviation Fuel (SAF), which have been proven by extensive investigations to be suitable for current gas turbine engines. However, these low-carbon fuels still contain a small percentage of carbon in their chemical composition. Thus, they still create a low carbon dioxide emission rate into the atmosphere, making them only an interim solution. Therefore, carbon-free fuels like hydrogen or ammonia have become an appealing option and a target of study to verify if they are suitable for implementation in gas turbines while complying with safety regulations. To this purpose, Computational Fluid Dynamics (CFD) methods have become crucial tools in the investigation of low-carbon and carbon-free fuels since CFD allows comprehensive examination of a wide range of parametric variations in fuel or burner operating conditions while relying on experiments only to tune the model for accuracy. In this context, the present master’s thesis aims, through Converge™ CFD code, to develop a high-fidelity and robust computational model of the CMT-Clean Mobility & Thermofluids Institute swirled-stabilized atmospheric burners using methane as a reference fuel due to the availability of experimental data for validation. The resulting CFD case setup was then used to simulate a partially premixed mixture composed of 95% ammonia and 5% hydrogen as fuel and compare it with previous methane results. This second task seeks to contribute to the knowledge of flame characteristics generated by ammonia-hydrogen combustion and analyze them against methane results. The CFD model was tested over three different meshes to balance computational cost and accuracy in Large Eddy Simulation (LES). The base grid size, taken from previous CMT CFD investigations, was compared with a grid 50% coarser and 25% finer. Results showed that the coarser grid represented the conical flame shape but predicted higher localized heat release peaks and wider recirculation regions, with a 13% increase in radial velocity downstream. The finer mesh reduced RMSE by 34.3% compared to the base grid but increased computational time by 30.67% without significant improvement in flame structure. Additionally, U-RANS k−ε turbulence models were assessed against LES to evaluate accuracy versus cost. LES outperformed U-RANS despite being 44% more expensive, as k−ε cannot resolve turbulent scales and relies solely on modeling. Thermoacoustic characteristics were addressed by testing plenum and outflow boundary variations, using non-reflective features to dampen pressure and mass flow oscillations. An elliptical plenum proved better than cylindrical configurations for controlling thermoacoustic behavior without relying on non-reflective boundaries. Finally, the ammonia-hydrogen blend simulation revealed the impact of ammonia’s low energy content and laminar flame speed, resulting in a larger flame with 30% less heat release than methane, while hydrogen acted as a combustion promoter due to its higher energy content and reactivity. |
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