叶片旋转一周，攻角随方位角近似呈正弦曲线变化，力矩随之上下波动。传统变桨重在改善最大攻角对应方位角的叶片性能，且改善程度随攻角减小而减弱。提出在小攻角区域采用大桨角，在大攻角区域采用小桨角，重点改善小攻角区域性能的变桨思路。以采用NACA0012，高2 m和旋转直径2 m的两叶片H型风轮为研究对象，基于双盘面多流管模型，分析变桨方案下尖速比分别为4.5和5时，攻角、切向力系数、转矩和风能利用系数的变化规律。研究结果表明新变桨方案下小攻角区域的攻角、切向力系数、转矩，较定桨方案均有明显提高；增大了高性能区域范围，缩小低性能区域；风能利用系数在尖速比5时提高了18.9%。计算结果与试验结果及文献计算结果均吻合良好，证明了计算结果具有一定的精度。
赵振宙
,
严畅
,
王同光
,
许波峰
,
曾冠毓
. 基于双盘面多流管模型立轴风轮变桨方法研究[J]. 机械工程学报, 2018
, 54(6)
: 168
-174
.
DOI: 10.3901/JME.2018.06.168
When the blade of vertical axis wind turbine (VAWT) rotates along a circle, the angle of attack (AOA) versus azimuth follows the curve of sine function approximately. The oscillating AOA results in the waved torque. The traditional variable pitch technologies mainly focus on the performance promotion at the position with higher AOA. The smaller AOA the azimuth has, the smaller pitch angle is designed, and the smaller enhancement is obtained. A new variable pitch strategy is proposed:the smaller pitch angle is employed in the azimuth with higher AOA, while the bigger pitch angle is employed in the azimuth with lower AOA, and the new technology mainly focuses on improvement of aerodynamic performance of azimuth position with small angle of attack. A two-bladed H-type VAWT, employing NACA0012 airfoil and with height 2 m and rotation diameter 2 m, is chosen as research objective. Based on double multiple stream-tubes model, the variation rules of angle of attack, tangential force coefficient, torque and power coefficient are analyzed at the condition of tip speed ratios are 4.5 and 5. The results show that:the new pitch strategy effectively improves AOA, tangential force coefficient, torque and rotor power coefficient. The maximum power coefficient is increased by 18.9% at the tip speed ratio of 5. The zones of higher performance are amplified and the zones owned lower performance get narrowed. The computation results have good agreement with experiment results and the ones of reference, which proves that the results of the paper own high accuracy and credibility.
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