Seabed response to mooring lines for floating offshore wind

Project Description:

This PhD scholarship is offered by the EPSRC CDT in Offshore Wind Energy Sustainability and Resilience; a partnership between the Universities of Durham, Hull, Loughborough and Sheffield. The successful applicant will undertake six-month of training with the rest of the CDT cohort at the University of Hull before continuing their PhD research at the University of Sheffield.

Floating offshore wind turbines are anchored to the seabed by long mooring lines that must withstand decades of cyclic motion caused by wind, waves, and platform movement. These lines interact dynamically with the seabed, where repeated dragging and settling cause the sediment to deform and form trenches. These evolving seabed features change the line’s mechanical response and can affect the long-term stability and fatigue life of the mooring system. Current engineering design tools represent this interaction in simplified ways, unable to capture the grain-scale processes that govern trenching, remoulding, and pore-pressure variation.

This project will develop a new computational model to simulate seabed–mooring interaction at the particle scale. It will combine the Discrete Element Method (DEM), which tracks the motion and contact forces between individual sediment grains, with a lattice-based fluid solver representing the pore water. This coupled approach will make it possible to examine how sediments rearrange, lose strength, and generate excess pore pressures under cyclic loading. Using the Geotechnical Engineering Group’s in-house HYBIRD framework, the student will run high-performance simulations to investigate how soil density, permeability, and loading history influence trench formation and resistance degradation.

The findings will inform improved seabed models for floating wind design, helping the offshore sector develop safer, more reliable, and cost-efficient mooring systems while providing the candidate with advanced training in computational geomechanics and high-performance simulation.

Training and development

You will benefit from a taught programme, giving you a broad understanding of the breadth and depth of current and emerging offshore wind sector needs. This begins with an intensive six-month programme at the University of Hull for the new student intake, drawing on the expertise and facilities of all four academic partners. It is supplemented by Continuing Professional Development (CPD), which is embedded throughout your 4-year research scholarship.

You will receive in-house training on multiphase DEM–LBM modelling and code development using the HYBIRD framework within the Geotechnical Engineering Group. Additional training in high-performance computing and version control will be provided through the University of Sheffield HPC Centre, complemented by CDT and professional workshops on numerical geomechanics and offshore renewables. 

Entry requirements

If you have received a First-class Honours degree, or a 2:1 Honours degree and a Masters, or a Distinction at Masters level with any undergraduate degree (or the international equivalents) in Computer Science, Engineering, or Physics, we would like to hear from you.

If your first language is not English, or you require Tier 4 student visa to study, you will be required to provide evidence of your English language proficiency level that meets the requirements of the Aura CDT’s academic partners. This course requires academic IELTS 7.0 overall, with no less than 6.0 in each skill.

If you have any queries about this project, please contact Dr Alessandro Leonardi (a.leonardi@sheffield.ac.uk) 

You may also address queries about the CDT to auracdt@hull.ac.uk.

Watch our short video to hear from Aura CDT students, academics and industry partners:

Funding

The Offshore Wind CDT is funded by the EPSRC, allowing us to provide scholarships that cover fees plus a stipend set at the UKRI nationally agreed rates. These are currently £20,780 per annum at 2025/26 rates and will increase in line with the EPSRC guidelines for the subsequent years (subject to progress).

Eligibility

Research Council funding for postgraduate research has residence requirements. Our CDT scholarships are available to Home (UK) Students. To be considered a Home student, and therefore eligible for a full award, a student must have no restrictions on how long they can stay in the UK and have been ordinarily resident in the UK for at least 3 years prior to the start of the scholarship (with some further constraint regarding residence for education). For full eligibility information, please refer to the EPSRC website.

We also allocate a number of scholarships for International Students per cohort.

Guaranteed Interview Scheme

The CDT is committed to generating a diverse and inclusive training programme and is looking to attract applicants from all backgrounds. We offer a Guaranteed Interview Scheme for home fee status candidates who identify as Black or Black mixed or Asian or Asian mixed if they meet the programme entry requirements. This positive action is to support recruitment of these under-represented ethnic groups to our programme and is an opt in process.

Find out more

How to apply

Applications for this project will open in Autumn 2025 for September 2026 entry.

Interviews will be held online with an interview panel comprising of project supervisory team members from the host university where the project is based.  Where the project involves external supervisors from university partners or industry sponsors then representatives from these partners may form part of the interview panel and your supplementary application form will be shared with them (with the guaranteed interview scheme section removed).

If you have any queries about this project, please contact Dr Alessandro Leonardi (a.leonardi@sheffield.ac.uk) 

You may also address queries about the CDT to auracdt@hull.ac.uk.

References & Further Reading 

[1] Fernandez, G. V., Ferri, F., Eskilsson, C., Tagliafierro, B., & Palm, J. (2025). Trenching of mooring lines using a discrete element method approach. Innovations in Renewable Energies Offshore – Proceedings of the 6th International Conference on Renewable Energies Offshore, RENEW 2024, November, 427–435. https://doi.org/10.1201/9781003558859-47 

[2] Rui, S., Xu, H., Teng, L., Xi, C., Sun, X., Zhang, H., & Shen, K. (2023). A Framework for Mooring and Anchor Design in Sand Considering Seabed Trenches Based on Floater Hydrodynamics. Sustainability (Switzerland), 15(12). https://doi.org/10.3390/su15129403 

[3] Rui, S., Zhou, Z., Gao, Z., Jostad, H. P., Wang, L., Xu, H., & Guo, Z. (2024). A review on mooring lines and anchors of floating marine structures. Renewable and Sustainable Energy Reviews, 199(March), 114547. https://doi.org/10.1016/j.rser.2024.114547 

[4] Leonardi, A., Wittel, F. K., Mendoza, M., Vetter, R., & Herrmann, H. J. (2016). Particle-Fluid-Structure Interaction for Debris Flow Impact on Flexible Barriers. Computer-Aided Civil and Infrastructure Engineering, 31(5), 323–333. https://doi.org/10.1111/mice.12165 

[5] Ceccato, F., Leonardi, A., Girardi, V., Simonini, P., & Pirulli, M. (2020). Numerical and experimental investigation of saturated granular column collapse in air. Soils and Foundations, 60(3), 683–696. https://doi.org/10.1016/j.sandf.2020.04.004