摘要
采用大涡模拟湍流模型对前后缘波浪型结节改形风机翼型在雷偌数5×104下不同攻角的流动控制机理进行了数值研究。研究表明:相比于标准直翼型NACA0012,改形风机翼型在失速区得到了更平缓的升力曲线。在小攻角(α<12°)工况下,改形翼型的升力系数稍小,然而当攻角(α>12°)时,其升力系数明显提高,最高可达37%。改形翼型由于其前后缘沿展向呈正弦波浪型变化,在不同截面处的呈现出明显不同的尾迹结构,从而导致其表面自由剪切层发生扭曲。这种三维涡在其产生、发展以及推移过程中的相互作用,使得其三维尾迹涡结构在失速区能得到很好的控制,从而达到延迟流动分离及减小失速影响的目的。深入研究前后缘波浪型结节改形风机翼型尾迹结构的流动分布及物理特性等,对于揭示前后缘结节改形风机翼型流动控制机理具有非常重要的意义。
The effect of the protuberances leading and tailing edges on the aerodynamic characteristics of a Wind Turbine modi- fied airfoil is studied using the large eddy simulations. The control mechanisms of a varicose airfoil with different angles of attack at the Reynolds number of Re = 5 × 10^4 have been studied using the large eddy simulations. Due to the sinusoidal spanwise waviness of the modified airfoil, a more gentle lift characteristic is obtained during stall. For angles of attack less than the baseline stall angle of a NACA0012 airfoil（ α≈ 12°）, a lift coefficient reduction was observed for the varicose airfoils, while the lift coefficient increases up to 37% greater than that of a NACA0012 airfoil when the angle of attack is larger than the baseline stall angle of the NACA0012 airfoil. In general, the leading edge protuberances results in the flow separation delay occur, which result in the delay of the stall on the whole airfoil and reduces the abrupt drop of lift at stall condition. However, no drag reduction can be found using such modified airfoil. It is hoped that such modified airfoil will be helpful on the design of wind turbine to enhance their working efficiency.
出处
《流体机械》
CSCD
北大核心
2012年第3期27-31,共5页
Fluid Machinery
基金
国家自然科学基金项目资助(11172220)
中央高校基本科研业务费专项资金资助(2010-Ia-030)
高等学校博士学科点专项科研基金资助课题(200804971025)
