Mechanisms Of Multi-directional Breakup And Atomization Of Liquid Jets And Performance Analysis

Technology of breakup and atomization of liquid jets has been widely used inchemical industry, medicine, power engineering and other fields. As the system of modernagriculture industry, technical requirements such as environmental protection, and the newequipment for crop protection applicable to different job object is needed for research anddevelopment. At present, general air assisted sprayer or ordinary spray rod type of orchardused directly in newly-builted orchard will bring large amounts of pesticide waste andpesticide pollution. This article will study on mechanisms of multi-directional breakup andatomization of liquid jets, and use the theroy to guide design for new type of profilemodeling spray mechanism of the young orchard and nursery.In order to fully understand the absorption effect of different sizes of droplets of fruittrees, master the job parameter, and the atomization process of spraying device, andachieve the combination of agricultural machinery and agronomy, the article applys sprayperformance test-bed to test different spray nozzle performance about particle size, mistcone angle, spray capacity, and spray consistency, then select a suitable orchard sprayingnozzles for orchard spraying operation. Depending on the selected nozzles spray width,determine spray space dimensions, establishing a physical model of a droplet motion andEuler-Lagrangian models, modeling of spray space for profile arm operations in GAMBIT,and meshing reasonable. Selecting discrete phase model in FLUENT, setting the physicalproperties of the liquid phase and boundary conditions of spray model reasonable, makingsimulation of spray conditions.First of all from one direction study on the breakup and atomization of pesticide, andcarried out simulation calculation of single or double nozzle spray, get the cloud picturedatabase in the atomization field such as droplets trajectories, velocity, density, and theturbulent kinetic energy. The simulation results show that when spraying direction tohorizontal spray in thefield, gravity will have a larger effect on droplet trajectories;disturbance caused by jet will not only work on air, but also react against the dropletsmovement; when fog-cone intersection occurred there will be a collision, then mostdroplets will combine together and droplet speed will be increased. On the basis multi-directional breakup and atomization of pesticide analyzed. Apply the AIP sorftwareto desgin of spray profile of multi-joint arm, and based on the spray job spacing adjust thenozzle position and target, the9types of operation condition has been simulated in CFD,and the result show that: the best angle adjustment range on adjacent two-spray bars is0~40°. In increasing the profile arms of two adjacent spray angle of the process, the sprayconsistency of five nozzles will change from a vertical “philips” to a “broken line” basedon changes in the tree, then make every nozzle closer to target, and increased sprayingprecision and accuracy.The article use combine means of spray performance test-bed and CFD to analysismechanisms of breakup and atomization of liquid jets to apply theoretical foundation fordesign of profile modeling spray sprayer. According to the appearance of apple trees intrifecta orchard, determine the profile of the arm and the size of the nozzle arrangement.Determine the best angle adjustment range when profile arm working, according to thesimulation on the condition of profile arm operations in CFD. The article has importantmeans to improve accuracy of orchard spraying, reduce spray drift and deposition waste,guide the development of new types of spray profiling mechanism.