Passive Flow Control in Vertical Axis Wind Turbines

主要研究者：Evans，Simon提案编号：1336474机构：伍斯特理工学院题目：垂直轴风力涡轮机中的被动流控制本项目将研究被动流控制的使用，通过防止低叶尖速比下的动态失速来提高垂直轴风力涡轮机（VAWTs）的性能。还将评估该方案对风力涡轮机的性能改进。该研究将包括通过一个完整的旋转，在叶尖速度比的叶片失速的垂直轴风力涡轮机叶片的数值优化。 该优化将确定叶片设计和桨距偏移，以最大化被动流量控制方案的性能，同时最小化该方案在未失速时对叶片性能的影响。这种流动控制方案包括由失速条件下跨叶片存在的压差驱动的涡流发生器射流。 将使用MATLAB中的例程进行优化，该例程将变量传递到非定常RANS求解器FLUENT。优化后的叶片设计将用于在风洞中使用俯仰翼型进行的参数研究，并实施被动流控制方案。在此参数研究中，喷射孔尺寸和喷射方向等参数将发生变化。从实验中测量的时间分辨的升力和阻力将被用来估计涡轮机提供的轴功率的改善。这项研究将评估一种方法，以增加垂直轴风力涡轮机的扭矩和功率输送，提高其效率，将风能转换为轴功率，从而增加其潜力，为国家能源生产做出重大贡献。VAWT被视为特别有吸引力的城市和家庭发电市场，其中风的条件是不稳定的，风向可变。然而，动态失速导致的低效率使采用率很低。 这项研究将评估一种方法，以提高这些涡轮机的效率，通过控制动态失速在低叶尖速度比，从而使这些市场的增长。这将减少对电网的依赖，通过移动能源发电到使用点，有助于减少国家？中国对化石燃料的依赖，并通过增加可再生风能发电的比例来减少温室气体排放。该项目的基础教育，从事和培训本科生在国家的最先进的实验和计算方法，并提供高中科学教师与风能，他们可以在课堂上使用的课程单元。所有WPI本科生都必须完成一个初级团队项目，互动资格项目（IQP），和一个高级团队项目，主要资格项目（MQP）。每个相当于三个课程。 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2年内进行，并将开发和试点一个关于风能的课程单元，以在高中科学课程中实施。该课程单元将在WPI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。

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.