Understanding magnetohydrodynamic (MHD) effects upon liquid metals is a significant challenge for the design of prototype and commercial fusion reactors. The current understanding of MHD effects is limited due to the complexity of the phenomena. Experimental efforts such as the forthcoming and existing facilities at UKAEA’s Fusion Technology Facilities (FTF), including CHIMERA, the Liquid Metal Flow Apparatus (LLiMFA), and SmalLab are extremely valuable, but they are subjected to various limitations due to the cost, challenges in achieving reactor conditions and data obtainable from physical measurements.

Computational methods such as Direct Numerical Simulation (DNS) offer an additional possibility of “numerical experiments” that complement the physical experiments by producing extremely high-fidelity data. Outputs can be used to verify the performance of less intensive conventional Computational Fluid Dynamics (CFD) models, which remain lacking for MHD applications. Further, the outputs themselves will provide more detailed understanding of the fundamental phenomena expected in complex flow regions, such as that in manifold areas or liquid metal armour regions in divertor regions where excellent heat transfer is critical to performance.

This project will extend and apply an existing DNS tool, CHAPSim , developed initial at the University and now under open-source development by a UK consortium CCP-NTH (Collaborative Computational Project in Nuclear Thermal Hydraulics). The project will go beyond fundamental study and look into complex geometry or coupled physical phenomena relevant to fusion where MHD effects are particularly complex. The work will support experiments in facilities such as CHIMERA, LLiMFA, and SmalLab. The project will also seek to develop engineering solutions by making use of the valuable data and insight gained. For example, machine learning or other artificial intelligence methods may be used to leverage outcomes and formulate correlations and reduced order models used in lower fidelity modelling frameworks such as coarse-grid CFD.

The project will build upon and extend various nascent collaborations between UKAEA and the University of Sheffield (UoS). An existing project at the University is already developing the initial CHAPSim implementation of MHD effects so that this new PhD studentship can focus upon the application of simulations to real fusion components in terms of both geometry and conditions. Further, the project will interface closely with the Post-doctoral Research Associate project launched in 2024 under the UKAEA/UoS Collaboration Agreement that is investigating multiscale thermal hydraulic simulation for fusion.

Computational capability required for the project will benefit from the University’s high performance computing (HPC) system, Stanage , and access to ARCHER2 through allocations from UK Turbulence Consortium. Supervision will be provided by the Thermal Hydraulics and Advanced Engineering Simulation groups at UKAEA as well as academics at the university.

This PhD project may be compatible with part time study, please contact the project supervisors if you are interested in exploring this. For further information about the project please contact Shuisheng He [email protected]

The UKAEA supervision team will include Nakul Sashidharan, Thermal Hydraulics Group and Aleksander Dubas, Advanced Engineering Simulation Group.

This PhD project is part of the EPSRC Centre for Doctoral training in Fusion Power. For further details about the PhD programme please see the Fusion CDT website .