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

Location: MLH R

Mode of Employment: Full-time / Fixed Term

A Snapshot of Your Day
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.

How You'll Make an Impact

• Literature study on combustion models
• Investigation of elevated pressure gas turbine combustor model
• Hydrogen operating points at 2, 4 and 8 bar
• Application of most promising modeling approaches from an atmospheric in-house study
• Comparison of tabulated and finite rate combustion chemistry models
• Comparison of models for turbulence-chemistry interaction
• Comparison of species diffusion models
• Adaptive mesh refinement (AMR) coupled with the thickening flame model (TFM) to save computational cost at elevated pressure
• Operating point of an NG/H2 fuel blend
• Documentation

What You Bring

• Currently enrolled in a University to undertake a master's degree program in mechanical engineering, physics, chemical engineering or any other similar fields
• Experience with CFD tools, particularly STAR-CCM+
• Proficiency in numerical flow mechanics, including RANS and LES methods.Understanding of hydrogen combustion kinetics and its effects
• Expertise in validating numerical models using experimental data
• Ability to conduct scientific studies and effectively document results
• Familiarity with adaptive mesh refinement and other optimization techniques for numerical simulations

About the Team
Our Gas Services division offers Low-emission power generation through service and decarbonization. Zero or low emission power generation and all gas turbines under one roof, steam turbines and generators. Decarbonization opportunities through service offerings, modernization, and digitalization of the fleet.

Who is Siemens Energy?
At Siemens Energy, we are more than just an energy technology company. We meet the growing energy demand across 90+ countries while ensuring our climate is protected. With more than 94,000 dedicated employees, we not only generate electricity for over 16% of the global community, but we're also using our technology to help protect people and the environment.

Our global team is committed to making sustainable, reliable, and affordable energy a reality by pushing the boundaries of what is possible. We uphold a 150-year legacy of innovation that encourages our search for people who will support our focus on decarbonization, new technologies, and energy transformation.

Find out how you can make a difference at Siemens Energy: https://www.siemens-energy.com/employeevideo

Our Commitment to Diversity
Lucky for us, we are not all the same. Through diversity we generate power. We run on inclusion and our combined creative energy is fueled by over 130 nationalities. Siemens Energy celebrates character - no matter what ethnic background, gender, age, religion, identity, or disability. We energize society, all of society, and we do not discriminate based on our differences.

Rewards/Benefits

• Exciting insights into an international company
• Lay the foundation for your career with us

We value equal opportunities and welcome applications from people with disabilities.

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