Research On Erosion Characteristics Of Wind Turbine Blades Under Sand-Wind Environment

As wind turbines always operate in harsh environment of wind and sand for very long time, which will lead to the occurrence of erosion phenomena on the wind turbine blades and have great impact on the safe and stable operation as well as the energy output of the wind turbine. Therefore, studying the erosion behavior of the wind turbine blades is of great necessity.Firstly, based on the N-S equation, combined with RNG k-? turbulent model and DPM model, the erosion behavior of the wind turbine in wind and sand environment was calculated in the paper, the effect of the particle diameter, the dust concentration and the wind speed of the coming flow to the erosion of the wind turbine blades was studied. Secondly,combined with the erosion on the leading edge of the wind turbine blades which operating normally, the shape of the leading edge of the DU 96-W-180 airfoil was changed and the aerodynamic characteristics of the airfoil were calculated using CFD method. By analyzing the lift and drag coefficients and the characteristics of flow field, the influence mechanism of the erosion on the blade leading edge to the aerodynamic characteristics of the airfoil was studied in the paper.(1) The main results for the study of the erosion characteristics on the wind turbine blades are as follows:a) In the wind and sand environment, the erosion on the rotating wind turbine blades mainly focused on the leading edge and the pressure side of the blades, the area eroded most seriously located on the leading edge of the blade and the phenomenon was particularly serious near the tip; The area eroded less seriously located on the pressure side of the blades; The suction side of the blades almost did not be eroded except the leading edge;b) The particle diameter had greater impact on the distribution of the erosion area and the wear extent. the erosion rate increased first and then remained stable with the increase of the particle diameter; The larger the particle diameter, the easier the particle hit the blades, the greater the intensity of impact, and the more serious erosion caused by a single particle, and the worse following features with the airflow at the same time;c) The increase of the particle concentration had little effect on the erosionposition,however, the wear extent of the blades presented a linear growth law with the increase of the particle concentration.d) when the speed of the wind rotor keeps constant, the impact angle of the particle to the blade surface reduced at the leading edge. but increased on the other section of the pressure side with the increase of the speed of the coming flow, which lead to the erosion weakened on the leading edge and got severe on other section of the pressure side; The value of the erosion rate related to both the speed of the incoming flow and the impact angle of the particle.(2) The research results that the effect of the erosion on the leading edge to the aerodynamic characteristics of the airfoil are as follows:a) Pits and gouges had less impact on the lift and drag coefficient, but the delamination on the leading edge had significant impact on them, especially under great angle of attack, the lift coefficient reduced significantly and the drag coefficient increased sharply; And as the erosion becoming more and more serious, the extent of the reduction and the increase increased gradually.b) The erosion on the leading edge aggravated the flow separation near the trailing edge of the suction side of the airfoil and made the separation point moved forward; Pits and gouges had less impact on the flow near the leading edge of the airfoil; Delamination has great effect on the flow near the leading edge, as the delamination lead to the occurrence of steps on the airfoil surface, the flow separated first and then reattached the airfoil surface and moved forward when it passed the airfoil.