| Due to the unique wind and sand weather in Northwest of China,the wind turbine blades are impacted by sand particles causuing erosion and wear on the surface coating of the blades,which seriously affects the aerodynamic performance of the wind turbine blades and reduces the annual power generation of the wind turbine.Therefore,it is very important to establish the wear model of the wind turbine blade material to predict the wear of the wind turbine blades.First of all,to design a wind-sand wind tunnel test bed with controllable mass flow rate,and study the particle mass distribution in the test section.On the basis of the existing DC-type low turbulence wind tunnel,this test stand is equipped with a wind tunnel mixing section,a wind tunnel contraction section and a wind tunnel test section.The wind-sand wind tunnel test bed uses an independently designed screw sand conveying device to supply sand,the blower is used to convey the sand particles output by the screw sand conveying device to the mixing section of the wind tunnel through the discharge pipe,and mix with the wind tunnel flow,the sand particles finally pass through the wind tunnel contraction section enters the wind tunnel test section.In this paper,sand particles with a particle diameter of 0.4mm to 0.5mm are selected.Under the condition of wind speed of 10m/s in the test section,measure the particle mass distribution in the test section.Get these conclusions:(1)The flow of particle is relatively turbulent in the first 0.6m of wind tunnel test sectionand the particle flow is stable between 0.6m and 0.9m;(2)The particle mass distribution of the section 2 of the test section is related to the height of the pipe outlet,the particle mass flow rate of the section 2 of the test section is related to the sand transport rate of the pipe;(3)Through three regression functions,the particle mass distribution curve of each row of pipes at the test section is fitted,and obtain the particle mass distribution law at the test section cross section 2.(4)Through add the particle mass distribution at the section2 of the test section to get the theoretical superimposed value of particle mass distribution at the section2 of the test sectionis;take the test of nine pipe synchronous transport sand in the same condition to get the experiment value of particle mass distribution at the section2 of the test sectionis;by comparing the test value with the superimposed value,find that the superimposed value of the particle mass distribution at the section of the test section is the same as the test value,and the particle mass distribution of the test value is more uniform than the superimposedvalue;in the condition of nine pipe synchronous transport sand,the area with uniform mass flow rate at the cross section of test section 2 accupy about seventy percent of the entire test section 2.The numerical simulation method was used to study the inpact speed of 10m/s,different particle mass flow rates(1.125g/s,2.25g/s,4.5g/s,6.75g/s,9g/s),and different inpact angles(15°,30°,45°,60°,75°,90°)conditions of the erosion wear characteristics of the flat plate specimens,which are verified by comparison with relevant test data.The study found that when the inpact angle is 30°,60°,75°,90°,with the increase of the particle mass flow rate,the distribution position of the wear rate of the sample surface is basically unchanged,the total wear rate of the sample surface linear increases with the linear increase of the particle mass flow rate.As the inpact angle increases,the total wear rate of the sample surface decreased slightly in the range of 15° to 45°,it increased significantly in the range of 45°to 75°,but the total wear rate of the sample surface at 90° was lower than that at 75°,the total wear rate is the largest at 75°,and the total wear rate is significantly reduced in the range of 75° to 90°. |
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