| Spraying nozzle is the atomization device of the pesticide liquid, and it’s the key component of a spraymachine to realize spraying work. Compared with the conventional hydraulic atomizing nozzle, theeffervescent atomization spraying nozzle has the advantages of high atomization quality, strong penetratingpower, pray long range, low energy consumption and small liquid viscosity influence. The effervescentatomization spraying nozzle is a new liquid atomization spraying nozzle of the agriculture plant protection,researching in resent years. In order to make the advantages of the effervescent atomization spraying nozzlebe applied to the agriculture plant protection, deeply research is necessary for the effervescent atomizationspraying nozzle. Through the theoretical analysis, the combining methods of computer simulation andexperimental study, the paper systematically studied on the performance of the effervescent atomizationspraying nozzle.（1）According to requirements of plant protection spraying,, designed an effervescent atomizationspraying nozzle. Accordance with the relevant design requirements, using the three-dimensional designsoftware Solidworks, respectively optimizing designed on the overall structure and the main structure ofthis spraying nozzle. Based on the knowledge of hydrodynamic, with the experience and equations in thedesign of the spraying nozzle, calculated and analyzed the main structural parameters of the nozzle, anddetermined the design parameters. Meanwhile, according the droplets breaking mechanism and bubblesatomizing principle, the paper studied and analyzed the atomization process of the bubbles.（2）This paper designed an effervescent atomization performance test device, and definite theexperimental program and workflow in the experimental study. On the basis of previous studies, analyzedthe factors affecting the performance of the atomization nozzle, and determined the atomizationperformance evaluation, studied and analyzed the performance measurement methods. Selected the fourkey factors with gas flow, liquid flow, vent diameter and nozzle outlet diameter to make multi-factor test,taking droplet size and cone angle as the response indicators, using orthogonal rotational regressioncombinatorial design test scheme to make experimental study and performance evaluation.（3）This paper made use of Design-Expert8.0.6software to analyze and process the experimentalresults, and determine quantitative mathematical model between the impact factors and response indicators.Taked the second-order response surface optimization of the impact of each factor on the atomizationperformance and optimal ranges, as follows，gas flow:700L/h~800L/h, liquid flow rate:15L/h~20L/h, ventdiameter:1.0mm~1.2mm, outlet diameter:1.3mm~1.5mm. （4）On the basis of experimental studies, through the physical and mathematical models ofsimplifying assumptions, using FLUENT software, simulated the gas-liquid two-phase mixing inside anddownstream exit fog field of the nozzle. Simulated a mixing chamber pressure flow field distribution,velocity distribution, the volume fraction (concentration) distribution inside the nozzle; simulateddownstream of the nozzle exit velocity fog field distribution, the particle diameter distribution; analyzed thesimulation results and determined the appropriate variation. According to comparing and analysis withnumerical simulation and experimental study, this paper found that numerical simulation results andexperimental results coincide. |
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