B1 - Realistic fluid-structure-seabed design tools that work together, not in isolation

B - Fluid-structure Seabed Interaction

Status - published
Last updated on: 24/05/2022

Challenges/Opportunities

Many design tools and processes neglect non-linear effects and cover a single discipline in isolation, leading to poor design outcomes

Solution

Existing models need to be improved and coupled to provide integrated whole system design tools

Context And Need

There is a need to reduce the time required for the design process, and eliminate unnecessary conservatism where it exists, so that ORE systems can be optimised and made more efficient. Many existing design tools have significant shortcomings that mean conservatism must be built in. For example, the tools may not capture important non-linear effects, are not fully integrated across all the different disciplines involved in the design, are not coupled across the appropriate scales, or lack appropriate validation.

Summary

Design tools are used to predict how structures interact with the sea and the seabed, to test and improve designs. The current generation of simulation tools generally focus on one aspect ??? aerodynamics, hydrodynamics, structural dynamics or geotechnics ??? with simplified exchanges of data between them, meaning conservative simplifications must be made. Improving and coupling existing models will lead to better designs.

Impact Potential

More accurate whole-systems design models will enable faster and cheaper design up front. They also offer better assessment of the long-term performance of the design.

Design simulation can be applied to all ORE technologies, lowering CAPEX and OPEX and making investment more attractive.

Whole-systems simulations that better informs across the full performance and impact of ORE systems will contribute towards social and environmental acceptance. The existence of validated design tools ensures that new technologies can be adopted

Research Status

___________________________________________________________________________________________

Supergen ORE Hub - Flexible Fund Research

  • Impact of in-service oscillatory movement on insulation reliability of AC and DC cables serving offshore platforms
    Lead Institution: University of Manchester
    Offshore wind energy is central to UK’s ambition of reducing carbon emissions. Traditional fixed foundation wind farms have limitations due to their surrounding environment and congestion, whereas floating platforms provide utilisation of deeper waters and increased capacity, for example in the North Sea. The Floating Wind Joint Industry Project Report 2018 identified cables to be at the heart of priority innovation needs. Typically, cable assets contribute to 5-10% of the total investment costs for an offshore wind farm. However, cable failures cause the majority of the offshore power outages and account for approximately 80% of insurance claims in this industry. The hypothesis explored in this proposal is that repeated flexing of a cable significantly reduces the cable’s life expectancy through repeated extension and compression of the polymeric dielectric. In particular, the impact of dynamic strain on a failure mechanism known as electrical tree growth will be explored. Electrical trees are microscopic tree-like voids which grow inside the insulation that eventually lead to catastrophic asset failure. The project will work closely with ORE Catapult’s dynamic cable bend fatigue rig team in Blyth, to conduct the test trial combining the mechanical flexing and electrical treeing concurrently.
  • Cable scour from fluid-seabed interactions in regions of mobile sedimentary bedforms
    Lead Institution: Bangor University
    Growing demand for renewable forms of energy extraction highlights the essential role of subsea power cables. In 2018, UK’s operational offshore wind farms were using 1,499 km of export and >1,806 km of inter-array cables to transport 6,385 MW of electrical power. 43 array and export cable failures have been reported between 2007 and 2018, resulting from a number of reasons including sediment and sedimentary bedform mobility and accidents from e.g. dredging and benthic fishing. This proposal is the first to make detailed field measurements of scour development over a section of real subsea cable. Existing assessments of cable scour from state-of-the-art labs and numerical models have provided valuable insight but are inherently limited. This project aims to provide a validated benchmark scenario linking turbulent flow and scour development relevant to ORE subsea cables at local to centimetric scales. To allow industry to apply new knowledge in the development of upscaled lab experiments and numerical models to provide optimised methods for cable protection, particularly where array-scale effects may feedback to and modify seabed mobility over larger areas than expected.

_________________________________________________________________________________________

Links to Industry Priorities:

Offshore Wind Innovation Hub - roadmap data seabed structure interaction and fluid structure interaction

____________________________________________________________________________________________

We would also like to invite UK researchers and industry stakeholders within ORE to submit links to research projects, both past and present, for inclusion within the landscape.

Therefore, if you have a UK-based research project within an area of ORE that you feel is relevant to a specific research theme or challenge within the Research Landscape, click HERE to submit your research project to the research landscape.

____________________________________________________________________________________________

PhD projects in Offshore Renewable Energy

In order to better understand the breadth of ORE research currently being conducted in the UK, the Supergen ORE Hub has collated from its academic network, UK Centres for Doctoral Training and Industrial partners, a list of PhDs currently being undertaken in ORE.

Access a PDF of the list and find out more about including your PhD.

Return to homepage