可变喷射范围的喷药装置的仿真与实现

【作者】 戴星；

【导师】 谢守勇；

【作者基本信息】 西南大学 ， 农业机械化工程， 2008， 硕士

【摘要】 农药是指在农业生产中用于防治农作物病虫害、消除杂草的各种药剂的统称。从大量使用农药来防治病虫草害至今的几十年里,农药的使用对人类和社会的贡献是全世界人们都有目共睹的。在农业生产中,有效地使用农药不仅可以提高粮食产量,而且可以减轻人们的劳动强度:在非农生产中,农药也曾发挥了很大的作用。但是由于农药的使用存在较多的问题,使得大量的农药流失到非靶标环境中,这样不仅浪费了农药,还造成了严重的环境污染。解决这一问题的一条技术出路便是在精准施药技术思想指导下的施药机械的革新、改造。基于此思想,本文结合重庆市科技攻关项目“基于太阳能集成的灌溉低能耗远程控制系统研究”,研制了一种可变喷射范围的喷药装置。该喷药装置由步进电机带动,通过调节涡流室深度,改变喷雾角大小,实现根据植株外形定靶定形精准喷药。喷药装置的设计思路来源于可调式旋水芯喷嘴,因此本文首先从理论上分析了影响喷嘴喷雾角大小的因素:理想情况下,喷雾角只与喷嘴的结构有关。接着,本文利用计算流体动力学(CFD)软件FLUENT仿真模拟流体在喷嘴内的流动,研究喷雾角与喷嘴结构参数的关系,优化喷嘴结构,研制喷药装置,并通过仿真得到了喷药装置涡流室深度与喷雾角间的函数关系:L=f(θ),为后期喷药装置的控制提供了依据。最后,通过自制实验测试平台验证了喷药装置可变喷射范围的功能。此外,本文还详细介绍了利用FLUENT软件对喷嘴内流场进行数值模拟研究的过程与方法以及喷药装置的结构设计过程。实验结果表明:本文研制的定靶定形喷药装置能够在一定条件实现喷射范围的变化。更多还原

【Abstract】 Pesticide is a general designation of the various medicaments which are used to control insect and to eliminate weeds. From the large use of pesticide to control pest to today ,the contribution of the use of pesticide for human and social is known all over the world. In agriculture production, the effective use of pesticide not only increases grain production but also reduces the labor intensity; in the non-agricultural production, pesticide has played a significant role. There are many problems in pesticide applications. It makes large quantities of pesticide is lost into non-target environment. This not only wastes pesticide, but also pollutes environment. To solve these problems is to reform and reconstruct spraying facilities based on precision pesticide application techniques.The variable spraying-area of the spraying device is fabricated based on the above principle and under the Chongqing key Scientific and Technological projects: Research of Low-energy of Irrigation emote Control System based on solar energy. This device is driven by the stepper motor, and achieves precision-area and target spraying by adjusting the depth of swirl chamber to change the spray angle according to the scope of plantThe idea for designing the spraying device comes from the adjustable nozzle. So that the factors of spraying angle are analyzed theoretically firstly in this paper: The factors are the structure of the nozzle under ideal circumstances. Secondly, which a numerical simulationis carried out for the flow in nozzle by FLUENT soft is to research the relation of spraying angle and the structure of the nozzle, to optimize the structure of the nozzle, to fabricatespraying device, and to find the functional relation of the depth of swirl chamber and the s praying angle to control the spraying device : L = f(θ) .Finally, variable spraying-area of thefunction of the spraying device is testified through the self-made experimentIn addition, the process and the method of simulation by FLUENT software and the design process of the spraying device are introduced in detail.The experimental results show that the spraying device changes the spraying area in certain range.更多还原