Digital modelling of boiling heat transfer in water-cooled nuclear reactors

Are you passionate about accelerating the adoption of low-carbon energy sources through groundbreaking research and pushing the boundaries of engineering? Join the Department of Mechanical Engineering’s Thermofluids Group at the University of Sheffield for a fully-funded 3.5 years PhD focusing on the modelling and simulation of boiling heat transfer and the critical heat flux (CHF) in water-cooled nuclear reactors.

Boiling is a complex phenomenon that is essential to the operation of water-cooled nuclear reactors. CHF is a key safety limit for reactors and the highest heat flux before a vapour layer isolates the heating surface, and must never be exceeded to avoid overheating or fuel damage. At present, inaccurate and uncertain prediction of boiling and the CHF limit forces reactors to operate significantly below their theoretical limits. By developing computational models that go beyond current limitations, you will contribute to unlocking the safe operation of reactors at higher power levels, making current and next generation reactors more efficient and sustainable. With heating and cooling applications responsible for nearly 40% of global CO2 emissions, improved boiling models have potential for impact well-beyond the nuclear sector, by optimizing heat transfer processes across numerous industries and low-carbon technologies.

In this project, you will focus on the modelling of convective boiling heat transfer from first principles, extending and moving beyond the methods that are currently implemented in computational fluid dynamics (CFD). You will improve the modelling of the nucleate boiling regime, and extend capabilities to high vapour generation conditions that can trigger the CHF. In conditions approaching CHF, bubble interaction on the heating surface is intense. The assumption of individual, non-interacting growing bubbles at the basis of most present models cease to be valid, and a reliable CFD model of these conditions is not yet available. In your research, you will also harness the potential of machine learning by developing a data-driven boiling model derived from its physically-based counterpart, enabling faster and more stable CFD calculations. You will work in close collaboration with a project funded by an Engineering and Physical Sciences Research Council (EPSRC) award and with the close support of Rolls-Royce, Westinghouse and the UK Atomic Energy Authority. The developed, novel boiling model will be implemented in CFD, validated, and used to predict the CHF at pressurised water reactor high pressure (~ 16 MPa) operating conditions. 

Applicants should have (or about to receive) a degree in engineering, physics or applied mathematics that is at least a UK 2:1 honours grade or its international equivalents. Previous experience with coding and CFD programming is desirable but not mandatory. If you are interested in applying and wish to discuss any details of the project informally please contact Dr Marco Colombo (m.colombo@sheffield.ac.uk).

How To Apply

Applications should be made at: http://www.shef.ac.uk/mecheng/phd/applying. Applications should include:

-              Personal statement

-              Curriculum Vitae

-              Two reference letters

-              Degree transcripts to date