Master thesis: Modeling high pressure NG/hydrogen flames in gas turbine model combustors

The main goal of combustion technology development for gas turbines is to maximize the gas turbine efficiency by increasing the combustion temperature. This is limited by thermo-acoustic combustion stability on the one hand, and by limits for nitrogen oxide emissions on the other hand. Additionally, in the near future, the CO2 footprint is to be minimized by adding hydrogen to the fuel gas, posing an additional challenge. With the emerging shift in fuel to increasing hydrogen content, the focus of these efforts is on combustion development. 

Within the combustor development process, the CFD tool STAR-CCM+ is utilized to perform numerical flow simulations using RANS and LES methods, which are used to improve design iterations. The increasing demand for hydrogen admixture in products requires design tools to account for the effects and phenomena related to hydrogen combustion, which are important due to the higher reaction kinetics and sub-unity Lewis number effects associated with hydrogen combustion. Therefore, it is essential to ensure that reactive flow simulations provide accurate and reliable predictions, which requires basic validation of the simulation methodology to identify the required numerical models at elevated pressure. In this work, the goal is to identify a reliable LES modeling approach for accurate prediction of test cases in gas turbine model combustors. To achieve this, detailed experimental data will be used for model validation in STAR-CCM+. 

In a previous study at Siemens Energy, various approaches were evaluated at atmospheric conditions, and the most promising ones were identified. Building on the outcomes of this study, the current work will be structured accordingly.