A common feature of all Offshore Renewable Energy (ORE) systems is the need for energy extracted from either wind, waves or currents to be transmit to shore via cables. At present, existing cabling designs are generally inherited from fixed onshore/offshore wind or the offshore oil and gas sectors, and there is uncertainty in their effectiveness for floating ORE farms.
One key challenge is understanding the motions and corresponding loads that cables are exposed to, and how these are dependent on the state of the cable under different scenarios. Seabed conditions, device motions and method of connection to the floating devices are all expected to influence these loads. Cable failures occur primarily due to either or both extreme loads and fatigue damage
This PhD scholarship aims to utilise and develop physical and numerical modelling tools to characterise the behaviour of cables that are in suspension between two points, and hence help to minimise the likelihood of failure of these component. We will focus on two scenarios; suspension over varying seabed topology and suspension between two interconnected devices. The PhD objectives are to:
Establish protocols for, and carry out, scale model testing of cable response within the COAST laboratory.
Adapt existing numerical models to simulate the hydrodynamic forces and motions in the two cable scenarios. This will include use and development of existing mooring line models and/or fully non-linear OpenFOAM simulations.
Apply material modelling methods to model cable damage from both extreme loads and fatigue resulting from the modelled motions.
