Forced and Natural Turbulence Allowing Studies of Turbulent anIsotropic Conditions (FaNTASTIC- 1)

强迫和自然湍流允许研究湍流各向异性条件 (FaNTASTIC-1)

基本信息

批准号：
1701278
负责人：
Andrew VanLoocke
金额：
$ 69.02万
依托单位：
Iowa State University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-01 至 2021-12-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1701278&HistoricalAwards=false
关键词：
Forced Natural Turbulence Allowing Studies

项目摘要

The lower part of the atmospheric boundary layer (ABL) - the part of the atmosphere extending ~300 m from Earth's surface - undergoes rapid transitions with nocturnal cooling, resulting in rapidly evolving temporal and spatial properties of coherent eddies. Using a unique and highly instrumented observation region, this project will observe these variations (eddies) in detail. One set of in-situ and remote sensing instruments will be sited inside a 200-turbine wind farm (forced turbulence) and another set ~22 km away in a matched landscape of natural turbulence. The research team will build on prior modeling and measurement experience to produce new understanding of the boundary layer by comparing forced and natural turbulence.Intellectual Merit:The innovativeness of this study derives from the fact that turbulence generated by turbines or other landscape structures has a distinctly different spectral signature and subsequent distinct influence on atmospheric exchange processes than do natural landscapes, such as fields of corn/soybean. Coherent eddies, known to be the central feature of the ABL, are not represented correctly by Monin-Obukhov Similarity Theory (MOST). The high-resolution in situ measurements will provide a physical alternativeto MOST for stable conditions, which in turn will improve the skill of weather forecasts and simulations, particularly under stably stratified conditions. The project has three objectives: Objective 1. Characterize anisotropic and large coherent turbulence eddies (natural and forced) by use of a high-resolution near-surface turbulence-measurement tower, strategically placed two tall towers, and a sodar. How are they initiated during and after the early evening transition (EET)? What are the contributing factors to energy conservation as the ABL evolves under stably stratified conditions? Objective 2. Employ multi-resolution decomposition (MRD) and wavelet transform methods to identify events of coherent structures that show minimal low frequency (e.g., mesoscale) compared to high frequency (local turbulence) influences on turbulent covariances. How can these methods help refine descriptions of surface fluxes driven purely by local turbulence from those influenced by uniquely forced (turbines) or mesoscale (e.g., gravity waves, surface heterogeneities, and terrain) influences? Objective 3. Combine measurements and analyses of Objectives 1 and 2, together with mesoscale and LES simulations with WRF and other models, to develop new understanding of coherent eddy evolution and the role of turbulent potential energy (TPE) near the surface in response to radiative changes in the EET of the ABL. What is the model sensitivity to the relative magnitudes of TKE and TPE under various levels of stratification? What principles should guide the choice of coherent eddy length scales for simulating flow in stable stratification?Broader Impacts:1) Improved Scientific Understanding from this research will have broad scientific, societal and economic ramifications. The research results will cross-cut many STEM disciplines and provide new fundamental understanding in research areas of high national priority.2) Student Learning and Training. Results from the study will enhance the education and experience for students at all levels, with emphasis on developing scientists with disciplinary depth and ability to reach across disciplinary boundaries, capable of working effectively in teams.3) Outreach to Underserved Populations. At the graduate level the research team will take advantage of the Iowa State University's NSFIGERT award's aggressive plan for recruiting students from the University of Puerto Rico. At the undergraduate level, the team will collaborate with the IINSPIRE-LSAMP Alliance, of which ISU is a partner institution.4) K-14 Engagement. The research team will partner with ISU's new Wind Energy Student Organization (WESO) that has active outreach to both the K-12 and community college level.5) Bi-Directional Mentoring Hierarchy. Built on current and recent ISU NSF-funded wind energy projects under EPSCoR, IGERT, MRI, and REU, the research team has established near-peer mentorships recognizing roles of gender, ethnicity, personal interests, and temperament in pairing-for-success.

大气边界层的下部（ABL） - 大气的部分距地球表面约300 m - 经历了夜间冷却的快速过渡，从而导致相干涡流的时间和空间特性迅速发展。使用独特的仪器观察区域，该项目将详细观察这些变化（涡流）。一组原位和遥感仪器将位于200涡轮风电场（强迫湍流）中，而在匹配的自然湍流景观中，将位于约22公里的距离内。研究团队将基于先前的建模和测量经验，通过比较强制和自然的湍流来产生对边界层的新理解。IntlectualFure：这项研究的创新性源于这样一个事实，即涡轮机或其他景观结构产生的湍流具有明显的与天然景观（例如玉米/大豆田）相比，光谱特征和随后对大气交换过程的不同影响。连贯的涡流（已知是ABL的中心特征）并未由Monin-Obukhov的相似性理论正确表示。高分辨率的原位测量将为稳定条件提供最大的物理替代方法，这反过来将提高天气预报和模拟的技能，尤其是在稳定的分层条件下。该项目具有三个目标：目标1。通过使用高分辨率的近表面湍流测量塔，表征各向异性和大相干湍流（自然和强迫），战略性地放置了两个高高的塔楼和一个SODAR。它们在傍晚过渡期间和之后如何启动？随着ABL在稳定分层的条件下进化，能源节能的因素是什么？目标2。与高频（局部湍流）对湍流协方差相比，采用多分辨率分解（MRD）和小波变换方法来识别显示最小低频（例如中尺度）的相干结构的事件。这些方法如何有助于完善表面通量的描述，纯粹是由受到唯一强迫（涡轮机）或中尺度（例如重力波，表面异质性和地形）影响的局部湍流驱动的？目标3。将目标1和2的测量和分析与中尺度和LES模拟与WRF和其他模型结合在一起，以对相干涡流进化以及在表面附近的湍流势能（TPE）的作用开发新的理解，以响应辐射。 ABL的EET的变化。在各个分层级别下，模型对TKE和TPE的相对大小的敏感性是什么？哪些原则应指导选择一致的涡流尺度以模拟稳定分层的流量？更广泛的影响：1）从这项研究中提高科学理解将带来广泛的科学，社会和经济后果。研究结果将跨越许多STEM学科，并在高国家优先级的研究领域提供新的基本理解。2）学生学习和培训。该研究的结果将增强各级学生的教育和经验，重点是发展具有纪律深度和跨学科界限能力的科学家，能够在团队中有效工作。3）宣讲服务不足的人群。在研究生层面，研究小组将利用爱荷华州立大学的NSFigert奖的积极计划，该计划是从波多黎各大学招募学生的。在本科层面，该团队将与IINSPIRE-LSAMP联盟合作，其中ISU是合作伙伴机构。4）K-14互动。研究团队将与ISU的新风能学生组织（WESO）合作，该组织对K-12和社区大学级别进行了积极的宣传。5）双向指导层次结构。研究小组建立在EPSCOR，IGERT，MRI和REU下的ISU NSF资助的风能项目的基础上，研究小组已经建立了近乎共同的指导，以表彰性别，种族，个人利益和气质和气质在成对成功中的作用。