Study On Aerodynamic Performance And Erosion Characteristis Of Wind Turbine Under Sandy Environment

With the great change of energy structure,wind power generation is growing on leaps and bounds,and all systems that constitute wind turbines have made great breakthroughs and progress.However,In order to achieve higher power of wind turbine,the tower and blade becomes longer.This finally causes the centrifugal force,bending stress,air thermal stress,many other forces increases,In addition,the external environment such as snow,wind,rainstorm and insects will also cause erosion.In this paper,numerical simulation is used to investigate the aerodynamic performance and erosion mechanism of two-dimensional S809 airfoil and NREL Phase VI three-dimensional rotating blade in the sandy environment.Firstly,the grid-independent and turbulence models are verified for the 2D airfoil,and the lift drag coefficients are compared with experiments,then choose the SST k-ωturbulence model and the DPM discrete-phase model,select the group incidence method and the orbit density is10000.By analyzing the velocity,pressure and streamline of airfoil surface under three different sandy concentrations with particle diameters ranging from 5μm to 200μm,we obtained how the airfoil surface aerodynamic performance at low Reynolds number(Re=1×10~6)changes.The results show that at the same concentration,when the particle diameter is between 5μm～60μm,the sand particles show good winding characteristics,and the lift coefficient of the airfoil hardly changes,but the drag coefficient increases significantly,and this growth rate becomes smaller and smaller with the increase of particle diameter.Between 60μm～200μm,the gravity of the particles increases and decreases with the air bypassing effect,which causes a certain degree of wear by hitting the airfoil.The change of the lift resistance of the airfoil becomes more and more obvious as the concentration becomes larger.When the concentration reaches 0.1,at a large angle of attack,particles with diameters of 5μm～60μm bypassing will cause a significant reduction in the positive pressure region of the trailing edge,and the pressure difference between the upper and lower surfaces reaches a minimum at 60μm.In 60μm～200μm wing positive pressure region gradually increases,and the trailing edge winding effect weakens.Based on the two-dimensional airfoil simulation results,the NREL phase VI blade is used as the object of research,with the SST k-ωturbulence model and DPM wear model.From the blade surface erosion wear phenomenon found:the same wind speed,erosion begin from the blade leading edge,and spread to the blade middle and trailing edge with the particle size increases gradually.The particle size is not proportional to the blade surface erosion rate,but will greatly affect the surface erosion area,but no matter how the particle diameter changes,the maximum erosion rate are always in the leading edge.Erosion and particle bypass exacerbated the blade three-dimensional flow separation,resulting in uneven pressure distribution in the cross-section,the negative pressure region significantly increased,the leading edge part of the wear is serious,judged to produce a small separation vortex,resulting in the pressure point significantly shifted to the middle of the airfoil.