Wear Behavior And Vortex Characteristics Of Y-Type Screen Filters With Different Working Conditions:Numerical And Experimental Study

Y-Type screen filters are often used as the final stage filters in modern micro technology to effectively filter and separate suspended solids in irrigation water.This type of filter has excellent hydraulic performance,which can effectively extend its service life and ensure the efficient and reliable performance of micro irrigation systems.In order to explore the flow field,vortex characteristics and wear of Y-Type screen filters under different working conditions,this paper uses the fluid mechanics discrete element method coupling method,and applies computational fluid dynamics to carry out numerical simulation of five inlet flow velocities(0.5,0.75,1,1.25,1.5m/s)of the mesh filter,the angle between the outlet of five filters and the cylinder(35,40,45,50,55 °),and whether there is a deflector,Analyze the flow field characteristics of the filter under different inlet flow rates and filter angles,as well as the effects and changes of particle characteristics and wear characteristics under different inlet flow rates,filter angles,and the presence or absence of guide vanes,and conduct experimental verification on the reliability of the numerical simulation results.Through research,it is found that:(1)The water head loss of the filter and the wear distribution of the filter under different flow rates were measured through numerical simulation using FLUENT software by comparing the clean water and muddy water physical tests.By fitting the flow pressure drop formula,the errors of five groups of clean water tests and mathematical models were compared,which were5.74%,14.81%,8.61%,9.47% and 9.29%,respectively.Most of the errors were within 10%,meeting the prediction requirements,proving that the reliability of mathematical models under clean water conditions was high;Comparing the distribution of filter wear under muddy water,the distribution areas are similar,proving the reliability of the numerical simulation results under muddy water conditions.(2)As the inlet flow rate increases,the internal vorticity also increases.The maximum flow rate increases by 51.49% compared to the minimum flow rate vorticity,but the relative increase gradually decreases,and the increase rate of vorticity inside the filter gradually slows down;When the angle of the filter increases,the vorticity changes in the inlet pipeline and filter chamber of the filter are not significant,while the vorticity in the outlet pipeline increases.The area of strong vortices gradually expands,and the vorticity increase from small angle to maximum angle is 10.64%.(3)The cross section directions of both sides of the regularization helicity inside the filter are opposite.With the increase of the inlet flow rate,the helicity Degree distribution of the inlet and outlet pipes of the filter and the filter chamber does not change;As the angle increases,the helicity of the inlet pipeline and filter chamber of the filter remains almost unchanged,while a large number of vortex areas in the same direction in the outlet pipeline gradually decrease towards the outlet as the angle of the filter increases.(4)Q method and λ Both methods can accurately capture the vortex core regions of different intensities in the mesh filter,with consistent distribution of captured regions.The Ωmethod can simultaneously display the strong and weak vortices of the filter,and has similarities with the streamline map of the filter.(5)The average particle residence time of particles with a particle size of 0.2mm is one of the standards for measuring the filtration performance of the filter.The guide vane can effectively improve the average particle residence time of the filter.As the inlet flow rate increases,the average particle residence time of particles decreases and tends to a saturation value.As the filter angle decreases,the average particle residence time increases by 25.90%.(6)Under certain operating conditions,the guide vane can reduce the wear of the filter by54.01%.When the inlet flow rate increases,the overall wear of the filter increases sharply;When the filter angle increases,the wear of the 0-1.2 second filter is not affected,and it begins to increase with the increase of the filter angle at 1.2 seconds.In practical applications,selecting a 35 ° angle filter to operate at a low flow rate of less than 1 m/s will result in a smoother internal flow field and better hydraulic performance,which is also conducive to reducing the wear of the filter screen and improving the service life of the filter.