| Plant protection sprinkler is a key component of plant protection machinery,plant protection has a crucial role.Fan-shaped plant protection sprinkler head is currently a very wide range of applications in the prevention and control of agriculture,forestry,disease,pests,grass spray.Spray nozzle atomization of the quality of the nozzle often has a great relationship between the atomization performance.Sprayer nozzle atomization performance indicators are the main particle size,atomization angle and the distribution of droplets and so on.The droplet size as a spray atomization quality of a key indicator of the size of the droplet size is directly related to the quality of the spray quality,the nozzle performance is crucial to the merits.Compared with the large droplet,small droplet adhesion is better,the fog distribution is more uniform,but its penetration is no fog drops,so in the actual atomization process will be due to branches and leaves Of the barrier is not easy to reach the target crop roots,but also prone to drift in the liquid atomization process,waste of pesticides,pollute the environment.The atomization angle is the range of the fog distribution that reflects the spray of the nozzle.Droplet deposition uniformity is an indicator of the uniformity of distribution of the liquid during spraying.The three nozzles designed in this paper are all improved on the basis of fan nozzles.Therefore,in order to study the similarities and differences of the flow field inside the fan-shaped spray nozzle with different terminal shapes,this paper designs and simulates the flow field of the fan-shaped spray nozzle with different terminal shapes through solidworks and fluent software.Cavity diameter,nozzle length and grooving angle,the similarities and differences of the flow field inside the fan spray nozzle with different terminal shapes and the influence of different structural parameters on the internal flow field of fan-shaped spray nozzles with different terminal shapes were compared.The experimental study on the influence of structural parameters on the performance parameters of a typical AD fan-shaped nozzle was carried out in order to find the optimal structural parameter combination of different structural parameters on the atomization performance of the nozzle and the optimal atomization performance.The maximum degree Reduce pesticide residues and droplet drift,reduce pesticide waste and environmental pollution.1.Using the internal structure of the nozzle slot angle,cavity diameter,nozzle length as the main factor affecting the atomization of the nozzle,the use of fluent software for different terminal shape of the different structural parameters of the nozzle under the flow field of the simulation analysis The results show that the nozzles of AA,AD and DD type have different nozzle shapes.The pressure and velocity of flow field inside the nozzle are obviously changed when the internal structure of the nozzle changes suddenly.With the increase of the diameter of the lumen,And the change of pressure(velocity)at the entrance of the orifice is gradually increased.All three nozzles are on the same section of the nozzle inlet(outlet),the nozzle pressure is constant,and the nozzle velocity is in the form of a ring.However,the nozzle pressure in the cross section of the nozzle hole decreases in a ring shape from the wall to the center of the nozzle hole,and then increases.The velocity of the nozzle hole in the cross section increases gradually from the wall to the center.Three Different terminal shapes of the nozzles from the nozzle inlet to the nozzle outlet,nozzle internal flow field pressure gradually decreased,the speed gradually increased,the same structural parameters,the three different terminal shape,the velocity of the nozzle orifice section is AA>DD>AD in descending order,and the pressure of nozzle orifice section of AD nozzle is slightly larger than that of AA and DD.2.The representative AD-type fan-shaped spray nozzles were processed and trial-manufactured,and then the atomization performance indexes were tested using the spray performance comprehensive test bench.The experimental results show that three structural factors,including the cutting angle,inner cavity diameter and nozzle length,all have significant effects on the atomization performance index(droplet droplet size,atomization angle,and mist distribution uniformity)of the nozzle;The particle size of the droplets increases with the increase of the cutting angle,that is,VMD15°< VMD25° <VMD30°,the variation coefficient of the fog distribution increases first and then decreases with the increase of the nozzle length;The average values of particle size,spray angle,and mist distribution increase with the increase of the inner diameter,and the variation coefficient of the mist distribution decreases with the increase of the inner diameter.The factors affecting the atomization droplet size of the sprayer from the primary to the secondary are the diameter of the cavity> the angle of the groove> the length of the spray hole;the factors influencing the spray atomization angle of the spray nozzle are the length of the spray hole> the internal cavity Diameter>cutting angle;The factors that affect the variation coefficient of atomizing spray distribution of the nozzle are from the main to the second order: the length of the nozzle hole>the angle of the groove>the diameter of the inner cavity.Comparing the experimental data with the simulation results,the nozzle nozzle performance is best when the nozzle nozzle structure parameters are: ?=30°,d=2.5mm and l=4.0mm.It provides the basis for the future design,optimization and improvement of plant protection nozzles and research on plant protection equipment. |
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