Numerical analysis of aerodynamic characteristic for vertical axis wind turbine of trailing edge jet

Abstract:

To restrain the flow separation phenomenon on the airfoil surface and improve the aerodynamic performance of wind turbine blade, the blowing jet technology with high reliability is applied to the blade trailing edge of vertical axis wind turbines (VAWTs). The influence of different jet angles on the wind power coefficient, torque coefficient, single blade pressure and whole vorticity of the wind turbine was analyzed by numerical simulation. The results show that, when the optimum tip-speed ratio is 2.3,0° jet can reduce the shedding vortex frequency effectively and control the wake effect of blade with a better efficiency and operation stability than 0° jet. When the tip-speed ratio is lower, the peak torque of single blade is concentrated on the 120° phase angle, and 10° jet has a noticeable effect on improving the torque coefficient of the whole machine. When the tip-speed ratio is higher, there is a large positive pressure area on the pressure surface of the single blade airfoil, the wind energy utilization coefficient increases by 11% at most, and the aerodynamic performance is superior to that of the non-jet VAWT. The wind turbine reduces the axial load that the blade needs to bear and improves the output power of the wind turbine through trailing edge jet on the whole. The trailing edge jet of different angles reduces the flow loss on the blade surface and delays the flow separation effectively, which is particularly important to enhance the market competitiveness of VAWTs.