Numerical flow analysis of vertical axis wind turbines with morphing airfoils

变形翼型垂直轴风力发电机数值流分析

• 批准号: RGPIN-2017-06694
• 负责人: Paraschivoiu, Marius
• 金额: $ 1.6万
• 依托单位: Concordia University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712342
• 关键词: Numerical; flow; analysis; vertical; axis

A morphing airfoil has the ability to change its geometry in order to optimize the aerodynamic forces for a specific operating flow condition. This technology can be very effective when applied to vertical axis wind turbines (VAWTs), because the blades of these turbines encounter different angles of attack as they rotate. Variable pitch technology has been investigated in the past for the same purpose, but it is mechanically more difficult to implement and offers less flexibility than morphing airfoils. Control of the morphing shape is easier to implement and has a greater potential for optimizing the instantaneous torque generated by each blade. The proposed research will investigate morphing airfoils that change the geometry of the trailing edge, and therefore the camber line of the airfoil. Changing the geometry can be used to prevent dynamic stall, to increase power extraction in the leeward portion of the rotation, to distribute the load over the rotation cycle or as a breaking system. This research plan proposes an approach to understand the influence of morphing the geometry, in particular during dynamics stall. It also includes the development of a computational tool for predicting the power extracted by a VAWT for different morphing strategies. Computational Fluid Dynamics techniques are powerful tools to simulate fluid flow around complex geometries. Although computationally expensive, Large Eddy Simulation (LES) is a necessary model to study complex unsteady flows such as the one occurring during dynamic stall. Over the years, an in-house LES-CFD code has been developed by Prof. Paraschivoiu's research group, and validated for VAWTs. The objective of the current proposal is the further development of the numerical algorithms and software, and to use these to analyze flow over morphing wind turbine blades, as well as dynamic stall. Other important aspects of the research will be the investigation of an improved LES model and addition of new acceleration techniques that will reduce the significant computation time that LES typically requires.

变形的机翼具有更改其几何形状的能力，以优化特定工作流程的空气动力。当应用于垂直轴风力涡轮机（VAWT）时，这项技术可能非常有效，因为这些涡轮机的叶片在旋转时会遇到不同的攻击角度。 过去已经针对相同的目的研究了可变的音高技术，但是在机械上，实施机械性更难，并且提供的灵活性比变形机翼较少。控制变形形状更容易实现，并且具有更大的潜力，可以优化每个刀片产生的瞬时扭矩。拟议的研究将调查改变后边缘几何形状的变形机翼，从而改变机翼的倾斜线。更改几何形状可用于防止动态失速，以增加旋转的背风部分中的功率提取，以在旋转周期或破坏系统上分配负载。该研究计划提出了一种理解变形几何形状的影响的方法，尤其是在动力学失速过程中。 它还包括开发一种计算工具，以预测VAWT为不同变形策略提取的功率。 计算流体动力学技术是模拟复杂几何形状周围流体流动的强大工具。 尽管计算昂贵，但大型涡流模拟（LES）是研究复杂不稳定流量（例如在动态失速过程中发生的复杂流动）的必要模型。多年来，Paraschivoiu教授的研究小组已经开发了内部LES-CFD代码，并为VAWTS进行了验证。 当前建议的目的是进一步开发数值算法和软件，并使用这些算法来分析流动的风力涡轮机叶片以及动态失速。研究的其他重要方面将是对改进的LES模型的研究，并添加新的加速技术，以减少LES通常需要的大量计算时间。