摘要
风力机叶片是使风能转化为机械能的原动机构,是风力机的重要部件,风力机风能利用系数的高低主要取决于其叶片的气动外形。保持直叶片垂直轴风力机使用的NACA0022翼型的对称性不变,改变其叶片最大厚度前部的形状,以期得到高风能利用系数的垂直轴风力机翼型。利用Fluent软件,采用k-ωSST湍流模型和SIMPLE算法,运用滑移网格技术,对由不同叶片构成的风力机进行数值计算。计算结果表明,当叶片最大厚度前部是长短轴比为3∶2的椭圆形状时,风力机的风能利用系数更高,而且处于高风能利用系数的尖速比范围更宽;在尖速比为1.72时,风能利用系数最高,为24.8%,此时的风能利用系数较基本翼型提高了28%。叶片修型提高风力机性能的物理机制是最大厚度点前移后的叶片在大攻角下的扰流流动分离强度减弱了。
The rotor of wind turbine is a driving mechanism, which transforms wind energy into mechanical energy, and it is an important component of wind turbine. Aerodynamic performance of wind turbine lies on airfoil of the blade. Based on the baseline airfoil of NACA0022 usually used in vertical axis wind turbine （VAWT）, the airfoil symmetry was kept, and shape in front of maximum thickness of the blade was modified to get an optimized airfoil for vertical axis wind turbine. VAWTs with different blades were simulated numerically using Fluent software. The k-ω SST turbulence model and SIMPLE algorithm were chosen, and sliding mesh technique was applied. When the modified part shape turns to a half ellipse with semimajor axis and semiminor of 3：2, the coefficient of power is larger, and the range with better aerodynamic performance widens. When the tip speed ratio equals to 1.72, the coefficient of power is largest, The largest Cp equals to 24.8%, which increases by 28% in contrast to baseline case. The mechanism of optimum is that the blade with a modification of airfoil can resist flow separation better at large attack angle.
出处
《可再生能源》
CAS
北大核心
2013年第12期63-67,共5页
Renewable Energy Resources
基金
辽宁省自然科学基金项目(20102177)
关键词
垂直轴风力机
气动性能
叶片修型
分离流动
vertical axis wind turbine （VAWT）
aerodynamic performance
modification of air-foil
separated flow
