Passive Flow Control in Vertical Axis Wind Turbines

垂直轴风力发电机中的被动流动控制

• 批准号: 1336474
• 负责人: Simon Evans
• 金额: $ 27.26万
• 依托单位: Worcester Polytechnic Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-15 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1336474&HistoricalAwards=false
• 关键词: Passive; Flow; Control; Vertical; Axis

PI: Evans, SimonProposal Number: 1336474Institution: Worcester Polytechnic InstituteTitle: Passive Flow Control in Vertical Axis Wind TurbinesThis project will investigate the use of passive flow control as a way to improve the performance of vertical axis wind turbines (VAWTs), by preventing dynamic stall at low tip-speed ratios. The performance improvements that the scheme enables in the wind turbine will also be assessed. The research will include numerical optimization of a vertical axis wind turbine blade through one full revolution, at a tip speed ratio for which the blade stalls. This optimization will identify a blade design and pitch offset to maximize the performance of a passive flow control scheme while minimizing the impact of the scheme on blade performance when not stalled. This flow control scheme consists of vortex generator jets driven by the pressure difference existing across the blade at stall conditions. The optimization will be performed with a routine in MATLAB that passes variables to the Unsteady RANS solver, FLUENT. The blade design resulting from the optimization will be used in a parametric study conducted experimentally using a pitching airfoil in a wind tunnel, with the passive flow control scheme implemented. Parameters such as jet hole size and injection direction will be varied in this parametric study. The time-resolved lift and drag determined from measurements taken in the experiments will be used to estimate the improvement in shaft power delivered by the turbine.This research will evaluate an approach to increase the torque and power delivery of vertical axis wind turbines, increasing their efficiency in converting wind energy to shaft power and therefore increasing their potential to contribute significantly to national energy production. VAWTs are seen as particularly attractive for the urban and home power generation markets in which wind conditions are unsteady and wind directions variable. However, low efficiency resulting from dynamic stall has kept adoption rates low. This research will evaluate an approach to improve the efficiency of these turbines, by controlling the dynamic stall at low tip-speed ratios, thereby allowing growth of these markets. This will reduce dependence on the grid by moving energy generation to the point of use, contribute to reducing the country?s reliance on fossil fuels and reduce greenhouse gas emissions by increasing the percentage of power generation by renewable wind energy.This project will utilize WPI?s project-based education to engage and train undergraduates in state-of-the art experimental and computational methods and to supply high-school science teachers with a curriculum unit on wind energy that they can use in the classroom. All WPI undergraduates are required to complete a junior team project, the Interactive Qualifying Project (IQP), and a senior team project, the Major Qualifying Project (MQP). Each is equivalent to three courses. MQP projects will be conducted over 3 years and will support the experimental and computational efforts. IQP projects will be conducted over 2 years and will develop and pilot a curriculum unit on wind energy for implementation in the high-school science curriculum. This curriculum unit will be developed with the support of WPIs unique STEM Education Center and the Worcester Public Schools, to address specific core ideas in the Massachusetts Science Standards, including conversion of energy and energy transfer, the relationship between energy and forces, and renewable energy.

PI：Evans，Simon建议编号：1336474机构：伍斯特理工学院标题：垂直轴风力发电机中的被动流量控制本项目将研究被动流量控制作为一种提高垂直轴风力涡轮机(VAWT)性能的方法，通过防止低叶速比下的动态失速。还将评估该方案在风力涡轮机中实现的性能改进。这项研究将包括垂直轴风力机叶片的数值优化，在叶片失速的情况下，通过一次满转的叶尖速度比。这种优化将确定叶片设计和螺距偏移，以最大限度地提高被动流量控制方案的性能，同时最大限度地减少该方案在未失速时对叶片性能的影响。这种流动控制方案由失速状态下叶片上存在的压差驱动的涡流发生器射流组成。优化将通过在MATLAB中的一个例程来执行，该例程将变量传递给非稳定RANS求解器FLUENT。优化得到的叶片设计将用于在风洞中利用俯仰翼型进行实验的参数研究，并实施被动流动控制方案。在这项参数研究中，喷孔尺寸和喷射方向等参数将有所不同。通过实验测量得到的时间分辨升力和阻力将被用来估计涡轮机输送的轴功率的改善。这项研究将评估一种增加垂直轴风力涡轮机的扭矩和功率输送的方法，以提高它们将风能转换为轴功率的效率，从而增加它们为国家能源生产做出重大贡献的潜力。在风力条件不稳定、风向多变的城市和家庭发电市场，VAWTs被视为特别有吸引力。然而，动态失速导致的低效率使采用率保持在较低水平。这项研究将评估一种提高这些涡轮机效率的方法，通过控制低速比下的动态失速，从而促进这些市场的增长。这将通过将能源发电转移到使用点来减少对电网的依赖，有助于减少国家S对化石燃料的依赖，并通过增加可再生风能发电的比例来减少温室气体排放。该项目将利用S项目教育来吸引和培训本科生使用最先进的实验和计算方法，并为高中科学教师提供一个可以在课堂上使用的风能课程单元。所有WPI本科生都被要求完成初级团队项目，互动资格赛项目(IQP)和高级团队项目，专业资格赛项目(MQP)。每道菜相当于三道菜。MQP项目将在3年内进行，并将支持实验和计算工作。IQP项目将在两年内实施，并将开发和试点一个关于风能的课程单元，以便在高中科学课程中实施。该课程单元将在WPIS独特的STEM教育中心和伍斯特公立学校的支持下开发，以解决马萨诸塞州科学标准中的具体核心思想，包括能量转换和能量转移、能量和力之间的关系以及可再生能源。