EAGER: Understanding fundamental mechanisms involved in turbulence, current and wave interactions for offshore wind-turbines

PI：Bhaganagar，Kiran Proposal编号：1348480机构：德克萨斯大学圣安东尼奥分校题目：EIGER：了解离岸风力涡轮机的湍流、水流和波浪相互作用涉及的基本机制近海风力涡轮机(WT)中的尾迹-尾迹相互作用与陆上风力涡轮机(WT)相比相当重要，这是由于海流和海浪诱导的强迫产生的额外负载。波浪强迫对尾流的影响一直是近海风浪设计的重要瓶颈之一。虽然风能已经成为一项成熟的技术，但海上风电在美国尚未实现。为了解决这一担忧，有强烈的动力推动对限制风力发电场性能的关键外部因素的基本了解。在这一方向上，本项目将通过使用大涡模拟(LES)作为一种工具来系统地了解波/流振幅强迫和风速对尾流-空气相互作用的影响，从而解决尾流-水流-空气相互作用所涉及的挑战。本研究的目的是确定风力机上的波流相互作用所产生的水动力。PI将根据动力强迫参数发展尾流区平均流动和湍流流动的标度律。这项研究的理论价值在于它是基本的，因为通过了解影响WT的关键流体动力和空气动力过程的相互作用，我们将能够根据尾流区的波/流/风的动力学参数来确定风速损失和湍流强度增强的尺度规律。这项研究具有变革性，因为近海WT近尾区的这些标度律将首次为现有的尾流模型提供准确的参数化。本研究将促进对近海风浪尾流区以下3个基本方面的基本认识：(1)修正表面粗糙度、平均速度亏损和尾流区湍流的尺度；(2)了解波能的非线性响应引起的共振；(3)隔离波生湍流、风生湍流和风生湍流。该项目的更广泛影响是与美国的能源危机直接相关，美国迫切需要使风能更容易获得，并且是可持续能源的主要来源。这一研究结果将为海上风电场的未来安装提供更现实的预测工具，对未来的海上风电场安装具有重要的指导意义。作为这项提议的一部分，有针对性的具体努力是鼓励更多妇女接受教育和从事工程工作。

PI: Bhaganagar, KiranProposal Number: 1348480Institution: University of Texas at San AntonioTitle: EAGER: Understanding fundamental mechanisms involved in turbulence, current and wave interactions for offshore wind-turbinesThe wake-wake interactions are quite substantial in an offshore wind turbines (WT) compared to onshore WT due to additional loading that arises due to sea current and wave-induced forcing. The effect of wave forcing on the wakes has been one of the important bottlenecks in the design of offshore WT. Though wind energy has matured to a technology, still offshore WT has not been realized in United States yet. To address this concern, there is a strong impetus to advance fundamental understanding of key external factors limiting the wind farms performance. Towards this direction, this project will address the challenges involved in the wake-current-air interactions by using large eddy simulation (LES) as a tool to systematically understand the effect of wave/current amplitude forcing and wind speed on the wake-wake interactions. The objectives of the current study are to determine the hydrodynamic forces due to the wave-current interaction on wind turbines. The PI will develop scaling laws of the mean and turbulence flow in the wake region in terms of dynamic forcing parameters. The scaling laws developed will be compared with the existing wakemodels.The intellectual merit of this study is that it is fundamental in nature as by understanding the interplay of key hydrodynamic and aerodynamic processes affecting the WT, we will be able to lay down the scaling laws of the loss of wind velocity and enhancement of turbulence intensity in terms of the dynamic parameters of wave/current/wind in the wake region. The research is transformative as these scaling laws in the near-wake region of offshore WT will provide, for the first time, accurate parameterization for the existing wake models. The present study will advance the fundamental understanding of the following 3 fundamental aspects in the wake region of offshore WT: (1) Scaling of modified surface roughness, mean velocity deficit and turbulence in the wake region (2) Understanding resonance due to the nonlinear response of the wave energy (3) Isolating the wave-generated turbulence, WT-generated turbulence and turbulence due to wind.The broader impacts of this project are its direct relevance to energy crisis in United States, where there is an urgent need to make wind energy more accessible, and a major source of sustainable form of energy. The results of this study will provide more realistic predictive tools, which will serve as important guidelines for future of offshore wind-farm installations. Specific efforts are being targeted as a part of this proposal to encourage more women to pursue education and careers in engineering.