定常吸气对风力机叶片气动性能影响的研究

RESEARCH ON THE INFLUENCE OF STEADY SUCTION AIR TO AERODYNAMIC PERFORMANCES

为改善风力机叶片的气动性能,在3.6 MW风力机翼型截面上开孔施加定常吸气,孔宽为1%~10%弦长,吸气压强为50~500 Pa。采用Spalart-Allmaras模型对多种工况进行数值模拟,研究定常吸气对翼型升阻力系数、力矩系数、失速性能、流动分离控制等气动性能的影响。结果表明:定常吸气扰动模式与流场主流的耦合能有效改善气动性能、推迟失速、延缓分离。定常吸气的引入使吸力面压强降低,吸力面和压力面的表面压差增大,从而提高了升力。定常吸气有效控制了流动分离,延缓了边界层的转捩,进而减小了阻力。阻力系数、力矩系数随吸气压强的增大而减小,升力系数随吸气压强的增大而增大。吸气最佳工况是孔宽为10%弦长、吸气压强为250 Pa。

To improve the aerodynamic performance of wind turbine blades there open a hole on 3.6 MW wind turbine the airfoil section with 1%-10%-chord suction hole width and 50-500 Pa suction pressure. A variety of experimental conditions has been investigated by the model of spalart-allmaras numerical simulating in order to achieve the purpose of explore the influence of the changes of pressure and width on coefficient of drag, lift and moment. The results showed that the coupling of steady suction air and the mainstream of flow field can effectively improve the profile performances, delayed the stall and flow separation. There get the following reasons for the increase of lift that benefits from the drop of pressure top of suction surface and the expand of the scope. The decrease of resistance benefit of the control of flow separation. As a suction pressure increases, moment coefficient drag coefficient become more and more little. But the lift coefficient on the counter. This gain become obvious with the increase of the hole width and summarizes that there is an optimal operating conditions which the hole width is 10%-chord with the suction pressure of 250 Pa for maximal benefits of improving profile performances.