Effects of grit roughness and pitch oscillations on the S814 airfoil
Effects of grit roughness and pitch oscillations on the S814 airfoil
复制标题
砂粒粗糙度和桨距振荡对 S814 翼型的影响
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
G. Gregorek
中科院分区：
文献类型：
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作者：
J. Janiszewska;R. R. Ramsay;M. Hoffmann;G. Gregorek
水平轴风力涡轮机转子在转子偏航时、转子叶片穿过支撑塔尾流时以及阵风时经历不稳定的空气动力学。对这种非定常特性的理解对于帮助设计新的旋翼翼型是必要的。由于表面粗糙度，转子还经历性能降低。这些表面不规则是由于昆虫碎屑、冰和/或老化过程的积累。对翼型的定常和非定常特性进行风洞研究有助于确定相关的流动现象，所得数据也可用于验证分析计算机代码。S814翼型模型在俄亥俄州州立大学航空航天研究实验室（OSU/AARL）3 × 5亚音速风洞（3 × 5）中进行了定常流和俯仰振荡试验。为了研究由于表面粗糙度导致的性能损失的程度，使用前缘砂砾粗糙度图案（LEGR）来模拟前缘污染。在完成基线情况后，LEGR被应用于稳态和模型桨距振荡情况。稳态条件下的雷诺数分别为0.75、1、1.25和1.5百万，攻角范围为-20 °至+40 °。当模型进行俯仰振荡时，在雷诺数为0.75、1、125和150万，频率为0.6、1.2和1.8 Hz时获得数据。在平均迎角为8 °、14 °和20 °时，使用了两个正弦波强迫函数{+-}5.5 °和{+-}10 °。出于本文的目的，对非定常条件的任何引用意味着模型处于桨距振荡中。
Horizontal-axis wind turbine rotors experience unsteady aerodynamics when the rotor is yawed, when rotor blades pass through the support tower wake, and when the wind is gusting. An understanding of this unsteady behavior is necessary to assist in the design of new rotor airfoils. The rotors also experience performance degradation due to surface roughness. These surface irregularities are due to the accumulation of insect debris, ice, and/or the aging process. Wind tunnel studies that examine both the steady and unsteady behavior of airfoils can help define pertinent flow phenomena, and the resultant data can also be used to validate analytical computer codes. An S814 airfoil model was tested in The Ohio State University Aeronautical and Astronautical Research Laboratory (OSU/AARL) 3 X 5 subsonic wind tunnel (3 X 5) under steady flow with both stationary model conditions and pitch oscillations. To study the extent of performance loss due to surface roughness, a leading edge grit roughness pattern (LEGR) was used to simulate leading edge contamination. After baseline cases were completed, the LEGR was applied for both steady state and model pitch oscillation cases. The Reynolds numbers for steady state conditions were 0.75, 1, 1.25 and 1.5 million, while the angle of attack ranged from -20{degrees} to +40{degrees}. While the model underwent pitch oscillations, data were acquired at Reynolds numbers of 0.75, 1, 1.25, and 1.5 million, at frequencies of 0.6, 1.2, and 1.8 Hz. Two sine wave forcing functions {+-}5.5{degrees} and {+-}10{degrees}, were used; at mean angles of attack of 8{degrees}, 14{degrees}, and 20{degrees}. For purposes herein, any reference to unsteady conditions means the model was in pitch oscillation.