Collaborative Research: On Wind Turbine Loads Assessment for Fatigue and Extreme Failure Limit States in Contrasting Atmospheric Stability Conditions

在过去十年中，风能的增长速度超过了所有其他可再生能源部门，年增长率超过25%。虽然这是令人鼓舞的消息，但风能也面临着三个技术挑战。首先，在设计过程中用于模拟湍流的模型没有涵盖可能引入关键事件的大气条件范围（例如，涡轮转子的高剪切），特别是在大平原地区。第二，在役的风力涡轮机老化，故障，特别是叶片复合材料的疲劳引起的故障，需要引起注意。最后，根据大气边界层建模和随机风力涡轮机气动弹性响应模拟的最新能力，需要改进设计理念和实践。这项合作研究旨在将风力涡轮机的设计范式扩展到基于可靠性的抗疲劳和极限状态性能评估。具体而言，将在反映一系列大气稳定条件的空间结构产生的各种流入湍流流场组合下评估涡轮负荷。提出的工作计划将侧重于基于无调谐大涡模拟和中尺度模式预报的四维合成湍流时间序列的开发。这些模拟气流将被输入到公用事业规模风力涡轮机的气动弹性模型中，该模型的响应统计数据将通过广泛的时域模拟来开发，这些模拟代表了长期不同的入流条件。在评估极限状态时将分析载荷极值，在评估疲劳极限状态时将分析累积损伤和寿命评估。将根据本研究的结果提出对现行设计规范的改进（例如由国际电工委员会提出）。这项研究具有创新性，具有潜在的变革性，因为它将使用真实的大气流动作为风力涡轮机模拟的入流条件。因此，所提出的研究将独特地实现在实际现场条件下风力涡轮机性能的模拟。更广泛的影响教育和推广活动以风能为中心。该教育计划将为学生提供机会，在大气科学和风能技术的界面上发展最先进的计算技术技能。桑迪亚国家实验室将为本科生和研究生提供风能技术的暑期实习机会。在K-12阶段，ppi与德克萨斯州中部和西部当地学区的教师建立了关系，创建了“迎风而行”/“工程一个清洁的明天”夏令营。

0967816/0967482Manuel/BasuIn the last decade, wind energy has witnessed faster growth than all other renewable energy sectors, with over 25% annual growth. While this is encouraging news, there are also three technical challenges facing wind energy. First, models used in the design process for simulating turbulence do not cover the range of atmospheric conditions likely to introduce critical events (e.g., high shear across a turbine rotor), especially in the Great Plains region. Second, wind turbines in service are aging, and failures, especially due to fatigue of composite materials used for blades, demand attention. Finally, refinements in design philosophy and practice are needed that are informed by state-of-the-art capabilities in atmospheric boundary layer modeling and stochastic wind turbine aeroelastic response simulation. Intellectual MeritThis collaborative research seeks to extend the design paradigm for wind turbines to the reliability-based assessment of performance against fatigue and extreme limit states. Specifically, turbine loads will be evaluated under various suites of inflow turbulence flow fields generated with spatial structure that reflects a range of atmospheric stability conditions. The proposed work plan will focus on development of four dimensional synthetic turbulence time series based on tuning-free large-eddy simulations along with mesoscale model forecasts. These simulated flows will feed into aeroelastic models of utility-scale wind turbines whose response statistics will be developed using extensive time-domain simulations representing varying inflow conditions over the long term. Load extreme values will be analyzed in evaluating ultimate limit states, whereas cumulative damage and life assessment will be analyzed in evaluating the fatigue limit states. Refinements to current design specifications (e.g. by the International Electrotechnical Commission) will be proposed based on findings from this study.This research is innovative and research is potentially transformative because it will use realistic atmospheric flows as the inflow conditions to the wind turbine simulation. Consequently, the proposed research will uniquely enable the simulation of wind turbine performance under realistic field conditions.Broader ImpactsThe education and outreach activities are centered on wind energy. The education plan will provide opportunities for students to develop skills in state-of-the-art computational techniques at the interface of atmospheric science and wind energy technology. Summer internship opportunities with Sandia National Laboratories in wind energy technology will be provided for undergraduate and graduate students. At the K-12 level, the PIs have established relationships with teachers at local school districts in Central and West Texas to create the Run on the Wind/Engineering a Clean Tomorrow summer camp.