"PhD Studentship: Advanced Coarse-Grid CFD for Nuclear Thermal Hydraulics Modelling"

University of Sheffield - School of Mechanical, Aerospace and Civil Engineering

Placed On: 4th February 2026

Closes: 12th March 2026

Partners: Co-sponsored by Westinghouse Electric Sweden AB, with support from STFC Daresbury Laboratory, the studentship is based in School of Mechanical, Aerospace and Civil Engineering at University of Sheffield.

Project Overview: Traditionally, nuclear reactor design and safety assessments rely on "sub-channel" (1D) and "system" (lumped-parameter) codes. While efficient, their simplifying assumptions limit accuracy when dealing with modern reactor design and complex safety scenarios. Conversely, high-fidelity Computational Fluid Dynamics (CFD) offers immense detail but remains computationally prohibitive for full-scale reactor design. To bridge this gap, we are developing a low-cost Coarse-Grid CFD (CG-CFD) approach. This methodology combines the industrial efficiency of sub-channel methods with the enhanced spatial modelling flexibility of CFD.

Scope of Work: Following a successful first phase focused on fundamental model development in OpenFOAM, this second phase will advance the CG-CFD methodology by:

• Developing advanced models for phase momentum and energy transfer.
• Validating predictions against high-quality experimental data (e.g., void fraction and pressure drop).
• Simulating 3D flow scenarios, including rod bowing, flow blockages, and part-length rods.

Impact: This research is critical for creating more accurate and robust thermal-hydraulic tools, directly supporting the optimization and safety of both current and next-generation nuclear reactor designs.

Person requirements: The successful candidates are expected to hold a first class or upper second-class degree in engineering, physics or applied mathematics. Interests in CFD, computer programming and nuclear engineering are desirable but pre-knowledge and experience are not essential. The student is expected to present their research outcomes to the project team/sponsors on a regular basis in both written and oral formats.

Funding: The studentship is primarily open to UK applicants. Exceptional EU and international candidates may be considered. The studentship is available to start in October 2026, covering the full tuition fees and providing an annual tax-free stipend is at UKRI rate (currently £20,780 p.a.) plus £4,000 per year top-up for 4 years. Generous funding is also available for training, and conference and workshop attendance.

How to apply: For further information and informal discussion please contact Professor Shuisheng He at s.he@sheffield.ac.uk. To apply, please use our on-line PhD application form, including your CV and two references and indicating on your form that you are replying to this advert.

Full tuition fees and an annual tax-free stipend at UKRI rate (currently £20,780 p.a.) plus £4,000 per year top-up for 4 years. Generous funding is also available for training, and conference and workshop attendance.

Closing Date: 12 March 2026 or until the position is filled.