Floating Offshore Wind Turbines: Conceptual Assessment of Highly Compliant Platforms using Theory, Design and Simulation

[133862] PI sweetmann该项目的目标是开发新的理论和数值工具，以准确模拟受大角位移影响的浮动海上风力涡轮机的行为，并利用这些结果评估潜在的下一代结构的经济和技术可行性。知识价值：将研究从高度刚性的风力涡轮机支撑结构到高度柔性的设计理念变化的可能性。将开发新的设计和操作控制系统，使塔能够根据风力显著倾斜，并将评估这些新设计的技术和经济优点。向高度合规结构的转变将是设计理念的重大转变，这与海上石油业务随着钻探和生产进入非常深的水域的变化是一样的。将开发一系列具有旋转恢复特性的新设计，从非常坚硬（由于风的影响，塔的倾斜很小）到非常柔顺（容易倾斜）。这些设计将充分详细地完成，以确定现有技术面临的所有挑战。计算这些高度柔顺结构的动力学既困难又重要，部分原因是巨大的旋转叶片的陀螺仪效应。这一挑战将通过一种新的动态模拟方法的理论发展和实际实施来解决，这种方法可以证明在风能领域之外对其他受大角位移影响的旋转设备是有用的。新方法将基于欧拉空间中角动量守恒的刚体云，代表一个漂浮的风力涡轮机。这种新的理论和模拟方法的发展是必要的，因为传统的风力涡轮机设计工具没有考虑角偏转的旋转顺序，因此不适合大的角运动。此外，整个系统是高度非线性的：环境强迫、静力恢复矩、时域控制系统和陀螺效应都是非线性的；准确的时域仿真是评估任何设计概念可行性的必要条件。证明高度兼容的支撑结构具有技术和经济价值，可以开启一场技术革命，使极具挑战性的深水海上风电场的经济发展成为可能。更广泛的影响：随着美国继续向“绿色”方向努力？？作为替代能源，人们对在海上安装风力涡轮机越来越感兴趣，因为那里有良好的风力和足够的空间。公众压力继续推动将这些设施建在远离陆地的地方，而且需要新技术来在非常深的水域更经济有效地发电。该提案首次探索了高度顺应结构的可行性，其结果可能是浮动风力涡轮机设计理念的巨大转变。教育和外联部分包括课程开发，研究生和本科生的教育，以及对K-12学生和教师以及有风险的大学生的外联。教学内容将包括开发有关海上风能的创新课程，教授海底和浮式海上风力涡轮机的设计，并将包括对快速发展的海上风力涡轮机设计领域的研究生和本科生的教育。向K？12名学生和老师将包括由PI和他的研究生在著名的“海上营地？？”德州农工大学加尔维斯顿分校；将通过一个既定的项目向处境危险的大学生伸出援手，其中包括许多历史上代表性不足和经济状况不佳的学生。

1133862 PI SweetmanThe objective of this project is to develop new theory and numerical tools to accurately simulate the behavior of floating offshore wind turbines subject to large angular displacements, and use those results to assess the economic and technical feasibility of potential next-generation structures. Intellectual Merit: The potential for a change in design philosophy from highly rigid wind turbine support structures to highly compliant ones will be investigated. New designs and operational control systems will be developed that allow the tower to lean significantly in response to the wind force, and the technical and economic merits of these new designs will be assessed. A shift to highly compliant structures would be a major shift in design philosophy paralleling that of the offshore oil business as drilling and production moved into very deep water. A family of new designs will be developed with rotational restoring properties ranging from very stiff (very small lean of the tower due to wind) to very compliant (leans easily). These designs will be completed in sufficient detail to identify all challenges to existing technology. Computing the dynamics of these highly compliant structures is both difficult and important, in part because of the gyroscopic effect of the huge whirling blades. This challenge will be met through theoretical development and practical implementation of a new dynamic simulation methodology that could prove useful beyond the field of wind energy to other rotating equipment subject to large angular displacements. The new method will be based on conservation of angular momentum in Euler-space for a cloud of rigid bodies representing a floating wind turbine. Development of this new theory and simulation methodology is necessary because conventional wind turbine design tools do not consider the order of rotation of angular deflections and so are inadequate for large angular motions. Additionally, the overall system is extremely nonlinear: the environmental forcing, hydrostatic restoring moments, time-domain control system, and gyroscopic effects are all nonlinear; accurate simulation in the time domain is necessary to assess the viability of the any design concept. Proof that highly compliant support structures have both technical and economic value could begin a technical revolution that enables economic development of wind farms in very challenging deepwater offshore locations. Broader Impacts: As the US continues to work towards ``greener?? sources of alternative energy, there is increasing interest in installing wind turbines offshore, where good winds and adequate space are both available. Public pressure continues to push for having these structures beyond sight of land, and new technologies are needed for more cost-effective generation of wind-powered electricity in very deep waters. This proposal explores for the first time the viability of highly compliant structures for that purpose, the result of which could be a dramatic shift in the design philosophy for floating wind turbines. The education and outreach components include course development, education of graduate and undergraduate students and outreach to K-12 students and teachers as well as to at-risk college students. The teaching will include development of innovative course curricula on off-shore wind energy to teach about design of both bottom-founded and floating offshore wind turbines, and will include education of graduate and undergraduate students in the rapidly advancing area of offshore wind turbine design. Outreach to K?12 students and teachers will be include presentations on offshore energy by the PI and his graduate students in the well-established ``Sea Camp?? program at Texas A&M at Galveston; outreach to at-risk college students, who include many historically underrepresented and financially disadvantaged students, will be through an established program.