Motions and loads on dynamic export cables for floating Offshore Renewable Energy farms using physical and numerical modelling.

所有海上可再生能源（ORE）系统的一个共同特点是需要从风、波或电流中提取能量，并通过电缆传输到岸上。目前，现有的电缆设计通常继承自固定的陆上/海上风电或海上油气行业，其对浮式矿石农场的有效性存在不确定性。一个关键的挑战是了解电缆所承受的运动和相应的载荷，以及这些载荷在不同情况下如何依赖于电缆的状态。预计海底条件、设备运动和与浮动设备的连接方法都会影响这些载荷。电缆故障主要是由于极端载荷和疲劳损伤引起的。该博士奖学金旨在利用和开发物理和数值建模工具来表征两点之间悬浮电缆的行为，从而帮助最大限度地减少这些组件故障的可能性。我们将重点关注两个场景；悬浮在不同的海底拓扑结构上，悬浮在两个相互连接的设备之间。博士的目标是：建立协议，并在海岸实验室进行电缆响应的比例模型测试。采用现有的数值模型来模拟两种情况下的水动力和运动。这将包括使用和开发现有的系泊线模型和/或完全非线性的OpenFOAM模拟。应用材料建模方法来模拟极端载荷和疲劳造成的电缆损伤。

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.