风送喷雾气流衰减与扩展规律分析与试验

针对果园风送喷雾对气流的特定需求,为了明确喷雾机出口处到果树冠层间的气流分布规律,在环向出风式喷雾机基础上,采用量纲法理论分析喷雾气流的轴向速度衰减规律、射流扩展规律,并在Ansys 15.0 Fluent平台上选用Realizableκ-ε模型仿真了初速度为10、15、20m/s下的衰减与扩展规律。同时,结合试验数据建立了喷雾气流衰减模型uc=0.5 7 8 u0x^-0.5,模型显著性检验F值小于临界值;气流边界扩展模型b=0.154 x,模型的决定系数为0.972 4。该研究可为果园风送喷雾机设计及气流场分析提供参考。

Test and Analysis on Air Attenuation & Diffusion Law of Air-assisted Spraying

Air velocity is vital important for air-assisted spraying in orchard. In order to clarify air distribution lay between the sprayer and the canopy. Based on ring outlet distribution of sprayer, dimensional analysis was adopted to analysis the axial velocity attenuation rule and jet extension rule. Fluent of Ansys 15.0 was used to simulate the air attenuation and diffusion law at the initial speed 10m/s, 15m/s and 20m/s with the Realizable κ-ε model.The air attenuation model was established with the test and simulation datas u c =0.578 u 0 x^-0.5 , the model test of significance F value is less than the critical value. Air flow boundary extension model is b =0.1542 x , model decision coefficient of 0.972 4. This research can provide the reference to design orchard sprayer and the flow field analysis.