Wind Tunnel Erosion Test And Model Study Of Wind Turbine Blade Coating

In China,land wind turbines are mainly distributed in Northwest and North China where dust weather occurs frequently.The blade surf ace of wind turbine will be worn to varying degrees due to particle erosion,which seriously affects the aerodynamic characteristics and power generation efficiency of wind turbine.In order to explore the erosion wear mechanism of particles on blade coati ng,the plate erosion wear experiment was carried out.At present,it is difficult to build a uniform wind sand flow field with traditional sediment carrying erosion device,which will have a certain impact on the study of erosion characteristics.In this paper,the wind sand two-phase flow field is constructed in a new wind sand tunnel to meet the test requirements.The influence of impact angle,wind speed,effectiv e cross-section mass flow rate and particle size on the erosion wear test results was studi ed by single factor rotation method.The erosion characteristics and erosion wear mechanism of coating materials under the influence of different erosion factors wer e explored,and the erosion wear prediction model was established,It provides a theoretica l basis for the study of wind turbine blade wear evolution in the wind sand environment.The wind tunnel erosion test was carried out on the coated plate sample of w ind turbine blade.The results show that:(1)The coating of wind turbine blade is a typica l plastic material.With the increase of impact angle,the wear of blade coating increases rapidly and decreases slowly,and the maximum wear occurs at 30 °,the max imum erosion rate occurred at 20 °;(2)The wear loss and erosion rate of blade coating increase with the increase of wind speed in the wind tunnel;(3)When the effective cross-section mass flow rate increases,the wear rate of the coating increases,and the erosion rate of the coating is not affected by it;(4)With the increase of particle si ze,the wear rate and erosion rate of the coating have particle size effect.The single particle wear increases with the increase of particle size,but the growth ra te slows down.The relative growth rates of the three particle sizes are 284% ～ 314% and 12 8%～ 153% respectively.Based on the bitter deformation wear theory and Finnie micro cutting theory,combined with the experimental data,the erosion wear model is m odified,and the modified erosion wear prediction model of wind turbine blade coating is pr oposed.Based on the Stokes number of particles,the erosion wear law of blade coating was studied,the results show that: When the Stokes number is different,the e rosion rate increases with the increase of Stokes number;When the Stokes numbers are the s ame,at 30 °～ 60 ° The erosion rate will decrease with the increase of the angle;When Stokes number and impact angle are the same,the change of other working condi tions will not cause the change of erosion rate.Based on the analysis of the erosion coeff icient and the change characteristics of sample surface morphology,combined with the experimental data,the erosion wear mechanism of wind turbine blade coating was studied,the results show that:(1)The total wear amount of wind turbine blade coating is composed of cutting wear amount and impact wear amount.The trend of cutting wear amount and total wear amount is the same,and the impact wear amount increases continuously with the increase of angle;When the impact angle is 30 °.The cutting effect is dominant,and a large number of "sand hole" pits are formed in the initial stage.With the continuous erosion behavior,the coating is repeatedly forged and extruded,and a "thin sheet" layer is formed on the surface.The cutting action makes the thin she et separate from the sample,and the "sand hole" pits evolve to deeper and wider places,and the "wave like" and "plough like" delamination are formed between the pits;When the impact angle is75 °.Normal stress is dominant.Continuous impact and weak c utting can still take away part of the coating surface quality.In the initial stage,a small amount of "sand hole" pits are formed.With the development of erosion behavior,only a small amount of "plough like" wear morphology is formed on the coating sur face,and the rest is "wave like" wear morphology.