Flexible Coupled Multi-Body Dynamic Research of Floating Offshore Wind Turbines

随着离岸风力涡轮机被建造在更远的离岸处和更深的沃茨中，将风力涡轮机安装在拴系到海底的浮动结构上而不是使用混凝土锚或驱动单极子的传统方法上变得越来越经济可行。将风力涡轮机安装在浮式结构上允许其位于更深的水中，这带来了更高和更一致的风载荷以及更大的公众接受度的好处，这是由于更低的视觉和环境影响，否则伴随着离岸风力涡轮机。但它们并非没有问题，在浮动结构上安装塔架和涡轮机极大地增加了系统的复杂性，因为它不仅必须保持浮力，而且还必须限制俯仰、横摇和垂荡的响应以及在各种条件下保持位置。过度的响应导致更高的结构应力，并且因此与具有减小的响应的系统相比，将招致更高的成本以使系统在结构上可靠，涡轮机的效率也由于俯仰和滚转中的大的旋转响应而降低，这也将增加对涡轮机部件的额外磨损，从而增加对修理和维护的需要。因此，能够预测浮动海上风力涡轮机（FOWT）系统由于其所承受的多个负载而产生的响应并减少这些响应对于成本有效、高效和安全的设计将是必需的。本计画的目的是提高FOWT动态响应预测的准确度，并发展一个数值程式来求解FOWT的气动-水力-弹性-系泊-伺服耦合方程式。该项目是由纽卡斯尔大学、ReNU博士培训中心和海上可再生能源弹射器合作开展的。该气动-流体-弹性-系泊-伺服数值程序将考虑在各种条件下作用在FOWT上的空气动力学、流体动力学和系泊缆的载荷，这将与结构和多体动力学相结合，以预测FOWT在各种海况下的响应。此外，控制理论将被应用，以识别阻尼和减少使用控制系统的FOWT的响应的方法。它将允许设计人员考虑不同的浮体概念，以及哪种浮体概念适合FOWT将被放置的操作区域。该程序将用于与其他规范以及已公布的流域实验数据或全尺寸测量数据进行规范间比较。它还将在海上可再生能源弹射器的支持下应用于7 MW FOWT的行业实践。 该项目由EPSRC东北大学可再生能源博士培训中心（ReNU）资助，通过EP/SO23836/1资助。

As offshore wind turbines are built further offshore and in deeper waters, it becomes increasingly economically viable to mount the wind turbine on a floating structure that is tethered to the sea floor rather than conventional methods of using a concrete anchor or driven monopoles. Mounting a wind turbine on a floating structure allows for it to be located in much deeper water which comes with the benefits of higher and more consistent wind loads as well as greater public acceptance due to lower visual and environmental impacts that otherwise accompany offshore wind turbines. But they are not without their issues, mounting a tower and a turbine on a floating structure vastly increases the complexity of the system, as it must not only remain buoyant but also limit responses in pitch, roll and heave as well as maintaining position in a large variety of conditions. Excessive responses lead to higher structural stresses and as such would incur higher costs to make the system structurally sound compared to a system with reduced responses, the efficiency of the turbine is also reduced by large rotational responses in pitch and roll which would also add additional wearing onto the turbine components increasing the need for repair and maintenance. As such being able to predict the responses of a floating offshore wind turbine (FOWT) system due to the multiple loads it is put under and reduce them would be required for cost-effective, efficient, and safe designs. The aim of this project is to improve the accuracy of dynamic response prediction of FOWTs and to develop a numerical programme to solve the aero-hydro-elastic-mooring-servo coupled equations of a FOWT. This project is undertaken in partnership between Newcastle University, the ReNU Centre for Doctoral Training, and the Offshore Renewable Energy Catapult. This aero-hydro-elastic-mooring-servo numerical programme will consider the loads from aerodynamics, hydrodynamics, and mooring lines acting on the FOWT in various conditions, this will be coupled with structural and multi-body dynamics in order to predict the response of the FOWT in various sea states. Furthermore, control theory will be applied in order to discern methods of damping and reducing the responses of the FOWT using control systems. It will allow designers to consider different floating body concepts and which concept of floating body would be suitable for the area of operation that the FOWT will be placed in. The programme will be applied for code-to-code comparison with other codes as well as with published basin experimental data or full-scale measured data. It will also be applied in industry practice with a 7MW FOWT with the support of the Offshore Renewable Energy Catapult. This project is funded by the EPSRC Centre for Doctoral Training in Renewable Energy Northeast Universities (ReNU) for funding though grant EP/SO23836/1.