PhD Studentship: Thermomechanical Design of New Gas Turbine Fuel Systems

Award details

This project will build on previous work on transpiration cooling5-6 to develop state-of-the-art Finite Element (FE) models informed by Computational Fluid Dynamics (CFD)4, to simulate the coupled dynamics of heat transfer, thermal-mechanical stress and hydrogen diffusion1 over repeated over combustion cycles. You will develop a versatile multi-physics approach for evaluating hydrogen embrittlement and fatigue-creep failure in stainless steel heat exchangers to aid the optimisation of geometric/flow parameters in engineering practise.

Transport, the UK’s biggest source of greenhouse gas emissions, presents a major obstacle to UK’s decarbonisation plans. To overcome it, we must develop new sustainable fuel technologies. Hydrogen is produced carbon-free, it offers the highest specific enthalpy of combustion amongst all fuels and gives water as by-product – it is expected to power mid-range aircraft, heavy good vehicles and 50% of buses by 2035. UK is scaling-up its hydrogen economy to unlock over 12,000 jobs and up to £11 billion investment by 2030, while the European aviation industry has committed to achieving hydrogen fuelled and hybrid-electric propulsion by 2050.

Scaling-up hydrogen economy entails both enormous benefits and challenges. Hydrogen is explosive and diffuses rapidly into metals, increasing their susceptibility to cracking1. Leakage by cracking of a hydrogen pipe will be catastrophic - 1 ton of hydrogen realised into the atmosphere corresponds to the emission of 13 tons of CO2 equivalent. Transport requires new fuel systems to be designed, capable of heating-pressurising liquid hydrogen (LH2) from its cryogenic storage conditions (-250 C) into conditions suitable for combustion (e.g. fuel tanks, pumps, heat exchangers)2-4. Jet engines require dynamic changes in fuel flow rate/pressure, implying that heat exchangers must facilitate transient cross flows of cryogenic fluid and hot fluid with extremely different temperatures, under corrosive hydrogen environment. This increases the likelihood of thermal shock and catastrophic failure.

This project will face the challenge of heating-pressurising cryogenic LH2 by investigating novel heat exchanger architectures (printed circuit type2-3), capable of surviving unprecedented thermal-mechanical stresses and simultaneous hydrogen uptake.

The project aligns seamlessly with the UK’s mission towards Net Zero and the large investments of world-leading turbine manufacturers on hydrogen technologies. A unique opportunity is presented to contribute to the pressing need for safe and efficient cryogenic hydrogen combustion, storage and supply, in order to phase-out fossil fuels and decarbonise our society. As a world leading institution in scientific computing, we aim to advance the current computational modelling capabilities in the broader area of mechanics under extreme complex environments.

The student will enjoy the opportunity to develop strong theoretical and computational modelling skills across allied engineering disciplines (heat transfer, solid mechanics, fluid dynamics, diffusion).

[1] Jeon et al. Thermal performance of heterogeneous PCHE for supercritical CO2 energy cycle. Int J of Heat and Mass Transfer. 2016.

[2] Huang et al. Review on the characteristics of flow and heat transfer in printed circuit heat exchangers. Applied Thermal Engineering. 2019.

[3] De la Torre et al. Design analysis of a printed circuit heat exchanger for HTGR using a 3D finite elements model. Nuclear Engineering and Design. 2023.

[4] Skamniotis et al. Crystal plasticity analysis of fatigue-creep behavior at cooling holes in single crystal Nickel based gas turbine blade components. Int J of Plasticity. 2023.

[5] Skamniotis et al. Multiscale analysis of thermomechanical stresses in double wall transpiration cooling systems for gas turbine blades. Int J of Mechanical Sciences. 2021.

[6] Zhang et al. Combined effects of stress and temperature on hydrogen diffusion in non-hydride forming alloys applied in gas turbines. Int J of Hydrogen Energy. 2022.

Award value

Funding is available for 3.5 years and covers tuition fees and a tax-free stipend.

Stipend: Tax-free stipend of approximately £21,870.34 p.a. with possible inflationary increases after the first year.

Bench Fees: PGR Research allowance from £1,000 p.a. to maximum £4,500 p.a.

Tuition Fees: UK tuition fees 25/26 £7,500 per year or International tuition fees 25/26 £32,400 per year.

These tuition fees may be subject to additional increases in subsequent years of study, in line with King's terms and conditions.

Note: A UKRI fully-funded studentship will only cover what is listed above. Applications should be aware there may be other costs which will not be covered by the studentship, for example, visa fees, healthcare surcharge, relocation costs and COVID-19 related quarantine costs.

Eligibility criteria

Applicants are required to hold/or expect to obtain at least a UK Bachelor Degree 2:1 in mechanical engineering, mechanics of materials, materials science, condensed matter physics, or relevant subject area.

Application process

To be considered for the position candidates must apply via King’s Apply online application system. Details are available on the Department of Engineering website.

Please apply for Engineering Research (MPhil/PhD) and indicate Dr Christos Skamniotis as the supervisor and quote the project title in your application and all correspondence.

Please upload a supporting statement, in PDF format, addressing the following elements: (1) Why are you applying to this PhD position, (2) How has your experience leading up to now prepared you to pursue a PhD, and (3) What are your short-term and long-term career goals, and how will an interdisciplinary PhD in Engineering and Physical Sciences help you to achieve them?

Please ensure to add the following code [EPSRCSkamniotis2501] in the Funding section of the application form.

Please select option 5 ‘I am applying for a funding award or scholarship administered by King’s College London’ and type the code into the ‘Award Scheme Code or Name’ box. Please copy and paste the code exactly.

The selection process will involve a pre-selection on documents and, if selected, will be followed by an invitation to an interview. If successful at the interview, an offer will be provided in due course.

Further information can be found at https://www.kcl.ac.uk/study/postgraduate-research/how-to-apply

Contact Details

Please contact christos.skamniotis@kcl.ac.uk for queries about the project.

If you require support with the application process, please contact pgr-engineering@kcl.ac.uk.