摘要
采用高升阻比翼型是提高风力机的风能利用率的重要途径,表面微结构在平板及飞行器上具有较好的减阻应用,在风力机翼型上的减阻研究相对较少。本文以弦长为600 mm的Ris?-A1-21风力机专用翼型为研究对象,在吸力面0.53弦长处布置6种不同的横向V型沟槽,基于ANSYS Fluent商用CFD软件,采用结构化网格和Transition SST紊流模型对不同的表面微结构进行数值计算,结果表明V型沟槽总长为4～7.5 mm,无量纲高度h^+和宽度s^+为10～18.5时,可以获得较好的减阻增升效果,在此范围内沟槽数量对翼型的减阻增升的变化规律影响很小,最大升阻比增率可达22.903%。当沟槽总长达到10 mm时,翼型的增升率减小,但其减阻率和升阻比增率优于沟槽长度小的方案。沟槽改变了翼型吸力面的压力分布,通过有/无沟槽的法向速度分析表明,微沟槽使得翼型表面边界层厚度减薄,表面速度梯度增大,从而使翼型的黏性阻力增加,因此V型沟槽的减阻效果主要由压差阻力的减小所引起的。
Airfoils with high lift-to-drag ratio used in blade can enhance power coefficient of wind turbine. Although drag reduction by microstructures on surface has been applied widely on flat plate and aircraft, it＇s hardly to see in the wind turbine airfoil field. Six different lateral V-grooves were laid on the suction surface of Ris？-A1-21 airfoil at the point of 0.53 c. The chord length of Ris？-Al-21 airfoil is 600 mm. ANSYS Fluent software with Transition SST turbulence model was used for hybrid grids of airfoils with microstructures. It was found that airfoil could attain efficient drag reduction and lift enhancement when the total length of V-grooves is between 4 mm and 7.5 mm and non-dimensional height and width both range from 10 to 18.5. Quantity of grooves have little effect on the change rule of drag reduction and lift enhancement. The maximum increasing rate of lift-to-drag could reach 22.903%. When the total length of grooves reaches 10 mm, lift enhancement ratio drops,but drag reduction ratio and increasing rate of lift-to-drag are both better than those in the scheme of smaller total length of grooves. Comparing normal velocity profile between grooves airfoil and smooth airfoil, the existence of grooves changes distribution of pressure and decreases thickness of boundary layer. The existence of V-grooves increases velocity gradient on surface and viscous drag of airfoil. To the total value of drag reduction, the pressure components of drag play a major role.
作者
袁一平
杨华
石亚丽
左红梅
YUAN Yi-Ping;YANG Hua;SHI Ya-Li;ZUO Hong-Mei(School of Water Conservancy and Energy Power Engineering, Yangzhou University, Yangzhou 225127, China;Goldwind Science ＆ Technology Co., Ltd., Beijing 100176, China)
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2018年第6期1258-1266,共9页
Journal of Engineering Thermophysics
基金
江苏省高校自然科学研究重大项目(No.13KJA348002)
扬州市扬州大学科技合作项目(No.YZ2016262)
江苏省高校自然科学研究面上项目(No.16KJB480003)
