Purpose

One of the best methods to improve wind turbine aerodynamic performance is modification of the blade’s airfoil. The purpose of this paper is to investigate the effects of gurney flap geometry and its oscillation parameters on the pitching NACA0012 airfoil.

Design/methodology/approach

This numerical solution has been carried out for different cases of gurney flap mounting angles, heights, reduced frequencies and oscillation amplitudes, then the results were compared to each other. The finite volume method was used for the discretization of the governing equations, and the PISO algorithm was used to solve the equations. Also, the “SST” was adopted as the turbulence model in the simulation.

Findings

In this paper, the different parameters of gurney flap were investigated. The results showed that the best range of gurney flap height are between 1 and 3.2% of chord and the best ratio of lifting to drag coefficient is achieved in gurney flap with an angle of 90° relative to the chord direction. The dynamic stall angle of the airfoil with gurney flap decreases were compared to without gurney flap. Earlier LEV formation can be one of the main reasons for decreasing the dynamic stall angle of the airfoil with gurney flap. Increasing the reduced frequency and oscillation amplitude causes rising of maximum lift coefficient and consequently lift curve slope. Moreover, gurney flap with mounting angle has a lower hinge moment than the gurney flap without mounting angle but with the same vertical axis length. So, there is more complexity in structural design concerning the gurney flap without mounting angle.

Practical implications

Improving aerodynamic efficiency of airfoils is vital for obtaining more output power in VAWTs. Gurney flaps are one of the best mechanisms to increase the aerodynamic performance of the airfoil and increases the efficiency of VAWTs.

Originality/value

Investigating the hinge moment on the connection point of the airfoil, gurney flap and try to compare the gurney flap with and without angle.

中文翻译：

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不同格尼襟翼安装角度的机翼的动态失速

目的

改善风力涡轮机空气动力性能的最佳方法之一是修改叶片的翼型。本文的目的是研究格尼襟翼的几何形状及其振荡参数对俯仰NACA0012机翼的影响。

设计/方法/方法

对于盖尼襟翼的安装角度，高度，降低的频率和振荡幅度的不同情况进行了数值解，然后将结果进行了比较。有限体积法用于控制方程的离散化，PISO算法用于求解方程。此外，在仿真中采用“ SST”作为湍流模型。

发现

本文研究了格尼皮瓣的不同参数。结果表明，格尼襟翼高度的最佳范围在弦的1％至3.2％之间，并且在相对于弦方向成90°角的格尼襟翼中实现了最佳的提升阻力系数。将带有盖尼式襟翼的翼型的动态失速角与不带盖尼式襟翼的翼型的动态失速角进行比较。早期LEV形成可能是降低带格尼襟翼的机翼动态失速角的主要原因之一。增加减小的频率和振荡幅度会导致最大升力系数升高，进而导致升力曲线斜率升高。此外，具有安装角度的盖尼式襟翼比没有安装角度但具有相同垂直轴长度的盖尼式襟翼的铰链力矩低。所以，

实际影响

提高翼型的空气动力学效率对于在VAWT中获得更多输出功率至关重要。格尼襟翼是增加机翼空气动力性能并提高VAWT效率的最佳机制之一。

创意/价值

研究机翼，盖尼式襟翼连接点的铰接力矩，并尝试比较带角度和不带角度的盖尼式襟翼。