Wind Tunnel Test Study On Sand And Dust Erosion Model Of Wind Turbine Blade Coating

In recent years,China’s onshore wind power has developed rapidly.The erosion and wear of wind turbine blade coatings in areas with frequent sand and dust weather will seriously affect the aerodynamic characteristics,power generation efficiency,maintenance costs and service life of wind turbines.However,no reliable sand erosion model for wind turbine blade coating has been established in the current research,and the surface wear of wind turbine blades cannot be accurately predicted.Therefore,it is necessary to investigate the erosion and wear characteristics of wind turbine blade coatings in service and to establish a prediction model for erosion in accordance with their properties,which is of great research significance and engineering application value for the study of wind turbine blade wear in sand and dust environment.In this paper,we adopt the factor rotation method to conduct relevant erosion tests on Mega polyurethane coating,a coating commonly used on wind turbine blades,on a wind tunnel sand erosion test bench to investigate the erosion pattern of sand and dust on wind turbine blades and to establish a sand and dust erosion prediction model that is consistent with the characteristics of wind turbine blade coatings.Through the processing and analysis of the test data of the flat plate sample of the coating,the erosion and wear characteristics of the wind turbine blade coating on the impact velocity,impact angle and particle size of the sand particles are obtained:(1)Under the same particle size and the same impact angle,the variation law of erosion rate and sample wear amount with particle impact velocity is basically the same: the sample wear amount increases with the increase of particle impact velocity by a power function law.It is more obvious when the speed is above 20m/s.(2)Under the same particle size and the same impact velocity,with the gradual increase of the impact angle,the wear of the sample shows a trend of first sharp increase and then decreasing.The wear amount of the sample is the largest when the particle impact angle is about 30°,while The particle erosion rate reaches its maximum value around 20°.The cutting action dominates the mass loss of the coating over the entire impact angle range.The coating has high elasticity and high wear resistance,so that the wear amount on the surface of the sample decreases continuously and the change trend becomes smoother and smoother under the large impact angle.(3)Under the same mass flow rate,impact velocity and impact angle,the variation law of wear amount and erosion rate with the particle size of sand and dust particles is consistent: the wear amount of the sample increases with the increase of particle size,and when the particle size is larger than 150 μm The wear growth becomes very slow.The sharp change in the number of particles at the same mass flow rate is the main reason for this rule,because the erosion amount of a single particle shows an obvious power-increasing trend with the increase of particle size.The prediction models for the erosion rate of wind turbine blade coating erosion were established by the least squares method,based on the commonly used E/CRC erosion model and General erosion model respectively,and combined with the erosion test data of wind turbine blade coating flat sample.Each part of the function in the model is well fitted and the predicted values of the model deviate less from the corresponding experimental results.The erosion models can better predict the erosion rate of the polyurethane coating material of the wind turbine blade,which provides an important basis for the numerical simulation research of the erosion wear of the wind turbine blade surface in the sand and dust weather.