Wind Turbine Wake Flow Field Analysis And Flow Control Technology Research

Wind turbine is operated in unsteady flow field, the output power of the wind turbine is directlyaffected by the flow field characteristics around it. In the paper, the airfoils flow field characteristicsand the wake characteristics of wind turbine are studied by numerical simulation, at the same time, theflow control technology like the tip vortex diffuser for wind turbine flow field control effect isstudied.1The flow field pressure, stream line distribution and the noise characteristics in different angle ofattack and velocity for airfoils of NACA4412and S809are studied, the results show that with theangle of attack and the velocity increases, the sound power level decreases appear to lag in the flowdirection, the noise characteristics is increased.2The wind turbine model was designed and created with the simplified windmill model. Thesurface pressure distribution of the blades and the three-dimensional effects range of the wind turbinetips were analyzed, the results show that better aerodynamic performance was appeared in75%of theblade length, and the three-dimensional effect range of the tip is about2%of the blade length. Then,the wake characteristics and the sound power level of the blades in different tip speed ratio areanalyzed, the results show that with the increase of the tip speed ratio, the wind turbine wake zonebecome larger and show swelling characteristics, the sound power level of the surface of the blade isalso increased with the increase of the tip speed ratio.3Based on the bionic noise reduction mechanism, the flow field characteristics of the serratedtrailing edge blade was studied, the result show that the blade with smaller teeth aspect ratio shows abetter noise reduction characteristic.4For the characteristics of wind turbine blade tip vortex, the control effect of the tip vortex diffuserwas studied. and the flow field noise characteristic was analyzed, the results show that the tip vortexdiffuser can effectively reduce the vorticity magnitude of the tip vortex and increase the wind energyutilization coefficient, at the same time, the tip vortex diffuser may also has the characteristics ofnoise reduction.