A Study on Relationship among Blade Camber Direction and Pitch Angle and Performance of a Small Straight-Blade Darrieus Wind Turbine by Using Scale Test Model and Gurney Flap
A Study on Relationship among Blade Camber Direction and Pitch Angle and Performance of a Small Straight-Blade Darrieus Wind Turbine by Using Scale Test Model and Gurney Flap
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DOI：
10.4236/jfcmv.2021.92003
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发表时间：
2021-03
期刊：
影响因子：
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通讯作者：
T. Tanino;K. Hara;Ryouichi Yoshihara;Takeshi Miyaguni
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文献类型：
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作者：
T. Tanino;K. Hara;Ryouichi Yoshihara;Takeshi Miyaguni
直叶达里厄型垂直轴风力发电机因其输出功率较高而被广泛应用于中小型风力涡轮机。在前期的研究中，我们利用升力型垂直轴风力机小尺寸试验模型研究了基于翼型弦长的性能与雷诺数的关系，结果表明，小直径试验涡轮机模型的性能明显低于大尺寸现场试验机，且其性能随叶片桨距角的变化也很明显。本文主要研究了小型直叶达里厄垂直轴风力机的性能，分析了叶片翼型弯度方向与桨距角之间的关系，并利用带有Gurney襟翼的小型平板垂直轴风力机试验模型对小型垂直轴风力机的性能进行了试验研究。在VAWT试验模型的叶片上安装了高度h与叶片弦长c之比h/c = 0.036 ~ 0.055的Gurney襟翼，此外，还检查了Gurney襟翼在叶片上的安装方向，包括转子的内侧和外侧，并检查了桨距角在-5至10度范围内的变化。并与无Gurney襟翼的垂直轴风力机的结果进行了比较，同时考虑了单叶片有/无Gurney襟翼的数值结果。结果表明，在俯仰角为10 °时，内、外Gurney襟翼的性能相反。也就是说，向内的格尼襟翼在小于10度的俯仰角处是上级的，而向外的格尼襟翼在大于10度的俯仰角处是有效的。此外，对于试验的小尺度模型，最佳俯仰角约为5 °，向内和较短的Gurney襟翼显示出更高的VAWT的功率性能在此俯仰角条件下。
Straight-blade Darrieus vertical axis wind turbines are used as medium and small size wind turbine because of higher power output in vertical axis wind turbine (VAWT). In our previous study, the relationship between the performance and Reynolds number based on airfoil chord length had been investigated by using small-scale test models of lift-type VAWT, and the results showed that the performance of tested wind turbine models with small diameter was clearly lower than that of the large-scale field test machine, and its performance also varies significantly with the blade pitch angle. In this study, we focused on the performance of a small-scale straight-blade Darrieus VAWT, the relationship among the blade airfoil camber direction and the pitch angle, and the performance of the small-scale VAWT was examined experimentally by using a small-scale VAWT test model with Gurney flap which was a small flat plate. Gurney flaps with its height h, as a ratio to the blade chord length c, h/c = 0.036 to 0.055, were attached to the blades of the VAWT test model, in addition, the attaching direction of the Gurney flap on the blade was examined for both inward and outward of the rotor, and the pitch angle was also examined for a range of −5 to 10 degrees. These results are discussed comparing with the result of the VAWT without Gurney flap and considering the numerical results for the single blade with/without the Gurney flap. The results showed that the performance of the tested VAWT was reversed between the inward and outward Gurney flaps around a pitch angle of 10 degrees. That is, the inward Gurney flap was superior at a pitch angle of less than 10 degrees, while the outward Gurney flap was effective at a pitch angle of more than 10 degrees. Furthermore, for the tested small-scale VAWT model, the optimum pitch angle was about 5 degrees, and the inward and shorter Gurney flap showed higher power performance of the VAWT under this pitch angle condition.