二相流气雾雾滴在大棚作物冠层的运动沉积机理研究

Due to the closed environment of the greenhouse and its high temperature and high humidity environment characteristics, pests and diseases in the greenhouse happened frequently. The high culture density of the crop, the unique stereoscopic characteristics of each crop and the lagging application technology make the pesticide droplets deposited in crop canopy nonuniformly. The prevention and control of pests and diseases in crop canopy is not complete, forcing the large capacity of pesticides, causing problems such as high operational risks of pesticide applicators, excessive pesticide residues, and environmental pollution. Therefore, a fixed pipe twin fluid cold fogger system is developed. The covered area of the system is not limited by the type of greenhouses and planting density, and can realize the operation of unmanned spraying in the whole greenhouse. For optimizing the operation performance of the system, improve the penetration ability and deposition uniformity of pesticide droplets in the crop canopy, laser scanning technology and CFD simulation technology is adopted in this project, to research the interaction mechanism of crop canopy shape, environment air flow field distribution and twin fluid aerosol droplets motion and deposition. The crop 3D canopy calculation model and the twin fluid nozzle layout and operation parameter requirements model based on the morphological characteristics of the canopy are established. The model was modified and verified by CFD simulation and spray test, taking pepper as an example. Finally, the optimal chemical application technical parameters of the system will be determined according to the morphology of plant canopy, so as to improve the uniform and effective deposition of pesticide droplets in crop canopy and guide the practical pesticide spraying operation.

温室大棚的封闭性及高温高湿的环境特点导致病虫害频发。棚内的高栽培密度和滞后的人工施药技术，使得农药雾滴在作物冠层无法均匀沉积，病虫害防治不彻底，迫使农药大容量多次数喷洒，造成施药人员作业风险高、农残超标、环境污染等问题。为此研发了固定管道式二相流常温烟雾系统，该系统气雾雾滴的覆盖区域不受设施种类和种植密度的限制，可实现棚室内无人施药作业。为优化本系统的作业性能，解决农药雾滴在作物冠层中的穿透和均匀沉积问题，本项目将采用激光扫描技术和CFD仿真技术研究作物冠层形态、棚内环境气流场分布规律与二相流气雾雾滴运动沉积的互作机理，建立作物三维冠层流场计算模型和基于作物墙冠层形态特征的二相流喷头布局及作业参数需求模型。并以辣椒为例结合CFD仿真和喷雾测试试验对模型进行修正和验证。最终实现依据作物形态确定系统的最佳施药技术参数，达到提高农药雾滴在作物冠层中均匀有效沉积的目的，指导实际生产的农药喷雾作业。

温室大棚的封闭性及高温高湿的环境特点导致病虫害频发。棚内的高栽培密度和滞后的人工施药技术，使得农药雾滴在作物冠层无法均匀沉积，病虫害防治不彻底，迫使农药大容量多次数喷洒，造成施药人员作业风险高、农残超标、环境污染等问题。为此研发了固定管道式二相流常温烟雾系统，该系统气雾雾滴的覆盖区域不受设施种类和种植密度的限制，可实现棚室内无人施药作业。为优化本系统的作业性能，解决农药雾滴在作物冠层中的穿透和均匀沉积问题，本项目将结合作物形态学、分形原理、3D建模和CFD仿真技术研究作物冠层形态、棚内环境气流场分布规律与二相流气雾雾滴运动沉积的互作机理，建立作物三维冠层流场计算模型和相关喷雾系统的智能管理平台。并以辣椒为例结合CFD仿真和喷雾测试试验对模型进行修正和验证。