Interactions of a Wind Turbine Array with a Thermally Stratified Atmospheric Boundary Layer: Flow Structures, Energy Fluxes and Modal Behavior

1034581CalIntelligence优点风力涡轮机阵列在高度可变的自然条件下运行，例如高度湍流变化性、地表地形和温度梯度。特别是，大气的热层结产生了热通量的垂直交换，这对气流的动能有直接的影响。风力涡轮机(WT)阵列对这些交换和层化大气的影响尚不清楚。深入了解这种相互作用可以延长风力机的寿命，最大限度地从风力机阵列中提取能量，并有助于了解这种阵列对大气的影响。拟议的研究重点是风洞中风力机阵列的流动、通量和能量学的实验研究。这项研究的目的是量化和了解层状大气湍流边界层(ATBL)与风力机阵列耦合的大气交换和功率提取。目前，研究层结是为了了解污染物的扩散，而风力机的研究主要集中在单个风暴流的叶片和尾迹的空气动力学上。这项拟议的研究将检查风力机阵列在热分层下的行为。这些实验研究将在波特兰州立大学(PSU)绿色建筑研究实验室(PSU)最先进的风洞设施中进行。层析粒子图像测速仪和冷线风速仪将分别用于测量实验WT阵列中的高分辨率速度图和温度图。结果将被浓缩成有用的参数和模式，可用于稳定和不稳定层结大气中的风力涡轮机阵列的微观、中观和全球模拟。这项拟议的研究旨在增进对热层结条件下从大气环境中提取风能的理解，最终促进在现实条件下的WT阵列的设计。布罗德影响教育计划强调本科生和研究生的跨文化和国际研究经验。将从图拉博大学(波多黎各)和巴黎州立大学招募三名本科生参加一个研究密集型暑期项目。这些学生将通过使用最先进的风洞测试和流动可视化设施来接触风能的工程方面。研究生将在夏季前往挪威，与挪威国防研究所(FFI)的研究人员就该研究的建模方面进行合作。外展计划强调让高中生接触STEM主题。该风洞设施具有使用基于网络的平台远程进行实验的能力。远程风洞实验将与Gladstone高中合作，在高中教室进行，让学生接触STEM和可持续发展主题。通过以学校为基础的项目，俄勒冈州MESA(数学工程科学成就)努力增加俄勒冈州少数民族和女性工程师的数量。PI和研究生将通过流体力学的实践实验与通过MESA计划招募的学生一起参加MESA日，并参观PSU风洞设施。

1034581CalIntellectual Merit Wind turbine arrays operate under highly variable natural conditions such as high turbulence variability, surface terrain and temperature gradients. In particular, thermal stratification of the atmosphere produces vertical exchanges of heat flux, which have direct impact on the kinetic energy of the flow. The influence of wind turbine (WT) arrays on these exchanges and the stratified atmosphere is not known. Insight on such interactions can prolong the life of the WTs, maximize power extraction out of the WT arrays, and help understand the impact of such arrays on the atmosphere.The proposed research focuses on an experimental study of flow, fluxes and energetics of wind turbine arrays in a wind tunnel. The goal of this study is to quantify and understand the atmospheric exchanges and power extraction on a stratified atmospheric turbulent boundary layer (ATBL) coupled with a wind turbine array. Currently, stratification is studied to understand pollutant dispersion, whereas wind turbine studies focus mainly on the aerodynamic of blades and wakes shed from a single WT. The proposed research will examine the behavior of wind turbine arrays under thermal stratification. These experimental studies will be carried at the state-of-the-art wind tunnel facility housed in the Green Building Research Laboratory at Portland State University (PSU).Tomographic particle image velocimetry and cold-wire anemometry will be used to measure high-resolution velocity and temperature maps, respectively, in the experimental WT array. Results will be condensed into useful parameterizations and models that may be used in micro, meso, and global simulations of wind-turbine arrays in a stably and unstably stratified atmosphere. The proposed research seeks to advance understanding of wind energy extraction from the atmospheric environment under thermal stratification to ultimately facilitate the design of WT arrays under realistic conditions.Broader ImpactsThe education plan emphasizes cross-cultural and international research experiences for both undergraduate and graduate students. Three undergraduate students will be recruited from Turabo University (Puerto Rico) and PSU to participate in a research-intensive summer program. These students will gain exposure to engineering aspects of wind energy by working with state-of-the-art facilities for wind tunnel testing and flow visualization. Graduate students will travel to Norway to during the summer to collaborate with researchers at Norwegian Defense Research Establishment (FFI) on the modeling aspects of the research.The outreach plan emphasizes exposure of high-school students to STEM topics. The wind tunnel facility has the capability to carry out experiments remotely using a web-based platform. Remote wind tunnel experiments will be carried out in a high school classroom in partnership with Gladstone High School to expose students to STEM and sustainability topics. Through school-based programs, Oregon MESA (Mathematics Engineering Science Achievement) strives to increase the number of minority and women engineers in Oregon. The PI and graduate students will participate in MESA Day through hands-on experiments in fluid mechanics with students recruited through the MESA program, complemented by tours to the PSU wind tunnel facility.