Development of downwind horizontal axis wind turbine for low wind speed condition

为了在低风速区获得与风速、风向变化相对应的高功率、高稳定性，对塔架下游侧旋转的顺风式小型水平轴风力机进行了试验研究。大型风力机的安装受到场地空间、空气动力噪声和电力波动等问题的限制。因此，小型风力机的发展有望成为当地的能源，在电力需求较大的城市地区也可以安装，但安装空间应该很小，而且由于在城市地区的普及，即使在低风速也能期望输出的条件被克服了。本研究对顺风式水平轴风力机的性能进行了评估。实验中改变了顺风式风力机的叶片桨距角，并对其性能进行了评价。此外，为了适应更广泛的应用，对翼型后掠角和前进角进行了不同程度的改变，并进行了试验。此外，将试验所用的转子应用于上风型水平轴风力机，阐明了顺风型风力机的性能，结果表明，下风型风力机的最佳桨距角与上风型风力机的最佳桨距角不同。此外，顺风型和上风型都认识到对前进角的变化很敏感，虽然变化幅度较小，但性能向后风型的变化较小。在最优的俯仰角下，下风型比上风型的性能有所变化，并且得到了后掠角和前进角的影响，得到了外观后悔的趋势。

An experimental research work on the small horizontal axis wind turbine of the downwind-type, which the rotor rotates on the tower downstream side, is done for obtaining high power with stability corresponding to the change of wind speed and wind direction in the low wind speed regionInstallation of large wind turbines is limited by the problem of a site space, an aerodynamic noise and the electric power fluctuation. Therefore, the development of the small wind turbine is expected as the local energy, which can be setup also in the city area where a lot of electric power demands exist However, installation space should be small, and the condition such as being able to expect the output even in a low wind speed be overcome as a condition because of popularization in the city areaThe performance of the downwind type horizontal axis wind turbine was evaluated as solution to these problems in this research. The blade pitch angle of the downwind type wind turbine was changed in the experiment and the performance was evaluated. Moreover, the airfoil sweepback and the advancing angles were variously changed to correspond to wide use and it experimented. In addition, the performance that applied the rotor used to experiment to clarify the feature of the downwind type to the upwind type horizontal axis wind turbineAs a result, the optimum pitch angle in the downwind type is different from those of the upwind type. Moreover, the downwind type and the upwind type have understood it is sensitive for the change in the advancing angle though are mild the change in the performance into the sweepback The downwind type was obtained in the optimum pitch angle than the upwind type, and moreover, the influence of the sweepback and the advancing angle was obtained and the appearance regret tendency was obtained