Optimisation of hydrogen and/or Ammonia based fuel utilisation in Gas Turbines

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Following the goals set by the European Green Deal and the UK's commitment to be powered entirely by clean energy by 2035, the topic of carbon neutrality and how to reach it has found centre stage in many political agendas. In 2021, electricity generation accounted for ~20% of total UK greenhouse gas (GHG) emissions making it the second largest single source. Decarbonising this sector is therefore vitally important if the ambitious net-zero goals are to be met. The use of hydrogen as a zero-carbon energy vector has gained significant interest in the past decade. The combustion behaviour of hydrogen is however very different to that of conventional fossil fuels. Hydrogen's reactive characteristics imply lower flame stability, higher NOx emissions, greatly modified thermoacoustic behaviours and enhanced risks of flashback and auto-ignition and therefore makes utilising high percentages of hydrogen in current lean premixed (DLE) systems very challenging. OEMs are investing significant R&D resources into the development of DLE systems capable of hydrogen-firing up to 100%. One of the main components receiving particular attention being gas turbine combustors and their auxiliary parts. The roughness of swirler wetted surfaces can affect axial velocities, heat release, NOx emissions and operability limits. Surface roughness should therefore be considered carefully starting from the design stage all the way through to manufacturing and post processing. Understanding the effect of roughness on boundary layer flashback (BLF) is of prime interest given hydrogen's increased risk of flashback.Research carried out by the student will focus on numerically modelling roughness effects. Simulations will be validated against experimental reacting an isothermal flow with the aim of better understanding roughness induced changes on the flow field (changes in velocity profiles, Swirl number, recirculation zones). Experimental work on the effect of roughness on H2 flames will also be performed. Findings will be able to inform OEMs on weather surface treatments of AM parts, such as polishing or artificially increasing roughness, are needed in turbomachinery components to improve performance particularly with regards to BLF, emissions and flame stability.