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首页> 外文会议>ASME(American Society of Mechanical Engineers) Energy Sustainability Conference; 20070627-30; Long Beach,CA(US) >SELF-STARTING HYBRID 'H' TYPE WIND TURBINE KRISHPERSAD MANOHAR
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SELF-STARTING HYBRID 'H' TYPE WIND TURBINE KRISHPERSAD MANOHAR

机译：自启动混合“ H”型风轮机克里斯帕瑟德马诺瓦尔

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Wind energy is one of the fastest growing alternative energy resources being taped into worldwide. Vertical axis Darrieus 'H' type lift turbines have the potential to compete effectively with the more widely used conventional horizontal axis wind turbines. However, a disadvantage is when the rotor is stationary, no net rotational force arises, even at high wind speed. The rotor must already be spinning to generate torque and the design is normally not self-starting. In this study a hybrid Darrieus 'H' type lift turbine was designed to operate as a self-starting drag type turbine at low rotational speed. With increasing rotational velocity the centrifugal force converted the drag type blades to full symmetrical airfoil sections making the turbine lift type. Design calculations, construction and testing of a two-blade prototype with 43 cm long blades, 14 cm wide, which formed a symmetrical airfoil of NACA 0018 profile when closed. The diameter for the turbine was 1.448 m and tests were conducted at six pitch angles with respect to the closed blade section (0°, 15°, 22.5°, 30°, 37.5° and 45°). Test results showed that the wind turbine was self-starting and the shaft speed increased linearly with wind speed at all angles of attack for moderate wind speed up to 10 m/s. However, the rate of change in shaft speed with wind speed showed an increase from 0° angle of attack to a critical 37.5° angle of attack and then decreased at 45° angle of attack. This observation is consistent with airfoil theory that greater drag forces exist at smaller angles of attack. A similar trend was observed for shaft power and turbine efficiency with maximum values of 49.5 W and 24 %, respectively, at a wind speed of 8.29 m/s for the 37.5° angle of attack. The tip speed ratio increased from a minimum of 0.83 at 0° to a maximum of 2.66 at 37.5° and then decreased at 45°. This indicated drag type operation (t.s.r. < 1) at small angle of attack and lift type operation (t.s.r. > 1) at higher angle of attack. This trend was consistent with theory as the drag force decreased the aerodynamic lift force increased with increasing attack angle, causing the blade speed to exceed that of the wind speed.
机译：风能是世界范围内发展最快的替代能源之一。垂直轴Darrieus'H'型提升式涡轮机具有与更广泛使用的常规水平轴风力涡轮机有效竞争的潜力。然而，缺点是当转子静止时，即使在高风速下也不会产生净旋转力。转子必须已经旋转以产生扭矩，并且设计通常不会自启动。在这项研究中，混合式Darrieus'H'型提升涡轮机被设计为在低转速下作为自启动阻力型涡轮机运行。随着转速的增加，离心力将阻力型叶片转换为完全对称的翼型截面，从而成为涡轮升力型。具有43厘米长叶片，14厘米宽叶片的两叶片原型的设计计算，构造和测试，在闭合时形成了NACA 0018轮廓的对称翼型。涡轮机的直径为1.448 m，并且相对于闭合叶片部分（0°，15°，22.5°，30°，37.5°和45°）以六个螺距角进行了测试。测试结果表明，风力涡轮机是自启动的，并且轴速随风速在所有迎角下线性增加，其中中等风速高达10 m / s。但是，轴速随风速的变化率显示从0°迎角增加到临界37.5°迎角，然后在45°迎角减小。该观察结果与翼型理论一致，翼型理论认为较小的迎角存在较大的阻力。对于迎角为37.5°的风速为8.29 m / s时，轴功率和涡轮效率的最大值分别为49.5 W和24％，观察到类似的趋势。刀尖速度比从0°的最小0.83增大到37.5°的最大2.66，然后在45°减小。这表示在小迎角下的阻力型操作（t.s.r. <1），在大迎角下的升降型操作（t.s.r.> 1）。这种趋势与理论相符，因为阻力减小，气动升力随迎角的增加而增加，从而导致叶片速度超过风速。

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