Circulation Control On The Blunt Trailing Edge Wind Turbine Blade

With the rapid development of the wind power industry,the wind turbine becomes larger and more intellectual.With the increase of the wind turbine blade length,the blade structural strength becomes more important.In the design of large-scale wind turbine blade,the blunt trailing edge wind turbine airfoil can be used to form the thickness range of the blade to improve the structural strength and reduce the surface sensitivity of the blade.However,the blunt trailing edge airfoil generally has a larger drag coefficient,and the stripping vortex generated behind the blunt trailing edge of the airfoil will exacerbate the noise of the blade.In this paper,the circulation control on a blunt trailing edge wind turbine airfoil and blade is implemented to achieve the lift enhancement,drag reduction and vortex stripping suppression.This paper focuses on the circulation control study by numerical simulation.The main works in this paper are as follows:1.The blunt trailing edge wind turbine airfoil was obtained after modifying the normal wind turbine airfoil.Both airfoils are numerically investigated by solving Reynolds-averaged N-S equations along with S-A turbulence model.The simulation method is validated by comparing numerical results and experiment data.The aerodynamic characteristics of the airfoil before and after the modification are analyzed.2.The trailing edge of the flatback airfoil is modified into a smooth curved surface to form a circulation control airfoil.Through the numerical simulation of the flow field around the circulation control airfoil,the aerodynamic coefficient and flow field are compared between circulation airfoil and flatback airfoil.The ability of lift enhancement and drag reduction of wind turbine airfoil circulation control method is analyzed.3.Through the numerical simulation of the flow field around the circulation control airfoil with different jet momentum coefficients(C?)and different jet slot heights,the influence of jet momentum coefficient and jet slot height on circulation control method of wind turbine airfoil is investigated.The two typical control regimes of separation control and super-circulation control are observed and analyzed by comparing the lift coefficient,drag coefficient and flow field of the circulation control airfoil under different jet momentum coefficients.4.The power consumption of the circulation control method under different parameters is analyzed.By estimating output power increase of the wind turbine under the circulation control,the economics and feasibility of the circulation control is analyzed,and the influence of jet slot height on control efficiency of circulation control is studied.The optimal value of jet slot height was initially determined.5.In order to improve the aerodynamic performance of the circulation control airfoil with the jet off cases and enhance the control effect with the large C? cases,the modification method from the trailing edge to the circulation control airfoil is improved.The control effect and energy efficiency of circulation control airfoils with different jet momentum coefficients are investigated.6.The ANSYS CFX software is used to simulate the blade of the NREL Phase-VI wind turbine,and the numerical simulation method of the wind turbine blade is verified.The NREL PhaseVI blade is modified as the circulation control blade,and the circulation control method of the blade is investigated.