WAKE MEDIATED COUPLING IN OSCILLATING HYDROFOIL TURBINE ARRAYS

振荡水翼涡轮阵列中的尾流介导耦合

• 批准号: 1509592
• 负责人: Matthew Bryant
• 金额: $ 34.56万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1509592&HistoricalAwards=false
• 关键词: WAKE; MEDIATED; COUPLING; OSCILLATING; HYDROFOIL

The objective of this project is to enable scalable arrays of damless oscillating hydrofoil turbines that will offer higher efficiencies, higher power output levels, and wider applicability than current hydropower technologies. The proposed work will take advantage of unique, recently uncovered wake-structure interactions that can increase power output and efficiency in densely packed arrays of oscillators. The approach of using oscillating hydrofoil devices that can be closely arranged together will open new markets for hydropower in locations previously considered too shallow or cluttered to be feasible. With many population centers located on coastlines and along rivers, this new source of clean energy would have minimal transmission costs and losses. Such devices could also be invaluable in off-grid sites like remote villages or temporary shelters for people displaced by disasters. Smaller scale applications could create flow-powered sensing stations that do not rely on short-term and environmentally hazardous consumable batteries for applications like monitoring critical infrastructure. At the utility grid scale, when compared to other renewable energy sources like wind and solar power, oscillating turbine hydrokinetic power arrays will offer more convenient integration into the power grid due to the predictable nature of the energy source. While wind and solar power are subject to daily variation and intermittency due to weather changes, tidal flows in particular can be accurately predicted well in advance, allowing the various sources in the utility grid to be readily balanced to cost-effectively meet demand and production allocations. In addition, the proposed education activities will serve to help broaden participation in engineering and inspire children to Science, Technology, Engineering, and Math (STEM) studies. North Carolina middle school and junior high school students will learn about flow energy harvesting and engineering design in a hands-on lab activity the researchers will develop and run as part of the popular NC State University summer camp program. The researchers will also broaden participation in research by providing opportunities for underrepresented undergraduate students from public colleges across North Carolina to engage in mentored research activities in the PI's and Co-PI's labs. Unlike traditional spinning turbines, which must be widely spaced to perform most effectively, our preliminary experiments have shown that oscillating energy harvesting devices actually perform most effectively when they are closely packed together and their motions become coupled by the wake flow. This work will determine how arrays of oscillating turbines can be modeled, controlled, and optimally configured to take advantage of these synergistic interactions between the wakes of upstream and downstream devices. Current wind and hydrokinetic energy research largely focus on the performance of individual devices from a mechanical or fluid dynamics standpoint, or the interaction and combination of power sources in a "smart grid" from an electrical perspective. The work proposed will leverage a different approach that exploits and optimizes interactions between devices at the mechanics level. Specifically, experimental and analytic studies will (1) investigate the parameters that govern the occurrence, strength, and scaling of the synergistic wake-structure coupling and how it can be used to enhance the performance of 2D arrays of hydropower energy harvesters. The researchers will also (2) quantitatively compare active, passive, and hybrid actuation and control approaches for the oscillating turbines, and (3) quantify the influence of the shallowness of the water body on the wake structure formation of individual and collective energy harvesters.

该项目的目标是实现可扩展的无坝振荡水翼涡轮机阵列，该阵列将提供比当前水力发电技术更高的效率、更高的功率输出水平和更广泛的适用性。提出的工作将利用独特的，最近发现的尾流结构相互作用，可以增加密集排列的振荡器的功率输出和效率。使用可以紧密排列在一起的振荡水翼装置的方法将在以前被认为太浅或杂乱而不可行的地方为水力发电开辟新的市场。由于许多人口中心位于海岸线和河流沿岸，这种新的清洁能源的传输成本和损失将最小。这种设备在偏远村庄或因灾害而流离失所的人的临时避难所等离网地点也可能是无价的。较小规模的应用可以创建流动力传感站，而不依赖于短期和环境危险的消耗性电池，用于监测关键基础设施等应用。在公用事业电网规模上，与风能和太阳能等其他可再生能源相比，由于能源的可预测性，振荡涡轮水动力发电阵列将更方便地集成到电网中。风能和太阳能由于天气变化而受到日常变化和间歇性的影响，特别是潮汐流量可以提前准确预测，从而使公用事业电网中的各种来源易于平衡，以经济有效地满足需求和生产分配。此外，拟议的教育活动将有助于扩大对工程的参与，并激发孩子们对科学、技术、工程和数学（STEM）的学习。北卡罗莱纳的中学生和初中生将在一个动手实验活动中学习流能量收集和工程设计，研究人员将开发并运行作为受欢迎的北卡罗莱纳州立大学夏令营项目的一部分。研究人员还将扩大对研究的参与，为来自北卡罗莱纳州公立大学的本科生提供机会，让他们参与PI和Co-PI实验室的指导研究活动。与传统的旋转涡轮机不同，传统的旋转涡轮机必须间隔很宽才能最有效地工作，我们的初步实验表明，振荡能量收集装置实际上在它们紧密排列在一起并且它们的运动与尾流耦合时表现得最有效。这项工作将决定如何对振荡涡轮机阵列进行建模、控制和优化配置，以利用上游和下游设备尾迹之间的这些协同作用。目前的风能和水动能研究主要集中在从机械或流体动力学的角度来看单个设备的性能，或者从电学的角度来看“智能电网”中电源的相互作用和组合。提出的工作将利用一种不同的方法，在力学层面上利用和优化设备之间的相互作用。具体而言，实验和分析研究将(1)研究影响尾迹-结构协同耦合的发生、强度和尺度的参数，以及如何利用尾迹-结构协同耦合来提高水电能量采集器二维阵列的性能。研究人员还将(2)定量比较振动涡轮的主动、被动和混合驱动和控制方法，以及(3)量化水体浅度对单个和集体能量采集器尾流结构形成的影响。