双层翼型直叶片垂直轴风力机动态气动特性研究

Research on dynamic aerodynamic characteristics of H-VAWT with double-layer airfoils

为进一步提高直叶片垂直轴风力机在大攻角状态下的气动性能,考虑双层翼型相互作用对翼型边界层状态的影响,基于数值模拟和正交实验方法,研究了双层翼型主要结构参数对直叶片垂直轴风力机动态气动特性的影响.结果表明:双层翼型间距是影响垂直轴风力机气动性能的主要原因;在最佳翼型间距与叶尖速比下,内层翼型对直叶片垂直轴风力机的扭矩系数平均贡献度约为29.5%,外层翼型对直叶片垂直轴风力机整体的扭矩系数平均贡献度提高了6.9%;双层翼型垂直轴风力机的内层翼型在提供扭矩系数的同时,也改善了外层翼型的流场特性;内外层翼型的相互作用能够有效增强直叶片垂直轴风力机的气动性能,双层翼型翼缝结构有助于提高流体动能,当叶尖速比为3时,翼型压力面尾缘附近流速最大提高约11%,进而使内外层翼型压力面和吸力面之间的压差增加,有效抑制了内外层翼型吸力面的边界层分离.

In order to further improve the aerodynamic performance of H type vertical axis wind turbine(H-VAWT)under high angle of attack conditions,the influence of interaction between double-layer airfoils on the boundary layer of airfoils was considered.Based on numerical simulation and orthogonal experimental methods,the effect of the main structural parameters of double-layer airfoils on the aerodynamic characteristics of H-VAWT was investigated.The results show that the spacing of the double-layer airfoils is the main factor that affects the aerodynamic performance of the H-VAWT.With the optimal spacing between double-layer airfoils and tip speed ratio,the average contribution of the inner airfoil to the torque coefficient of the H-VAWT is about 29.5%,while increasing the average contribution of the outer airfoil to the torque coefficient by 6.9%.The inner airfoil of a double-layer airfoils H-VAWT improves the flow field characteristics of the outer airfoil as it improves the torque coefficient.The interaction of the inner and outer airfoil can effectively reinforce the aerodynamic performance of the H-VAWT,while the slit structure of double-layer airfoils helps to increase the fluid kinetic energy,the maximum increase in flow velocity near the trailing edge of the airfoilpressure surface is 11%,when the tip speed ratio is 3,which increases the pressure difference between the suction surface of the inner and outer airfoil pressure surfaces and can effectively suppress the boundary layer separation between the suction surface of the inner and outer airfoil.