植保旋翼无人机田间喷雾作业的雾滴沉积规律研究

Unmanned Vehicle Helicopter(UVH) sprayer technology is a important tendency of crop protection industry in China，the research of deposition rules of UVH sprayer could promote the innovation and development of aerial spray technology. This project will study the droplet deposition and drift trajectory rules through simulation experiment, numerical simulation and field experiment; Design and build the flow simulation experiment system of UVH spray, build the CFD numerical model of rotor flow, research the applicable of turbulence model and validation of numerical model, the velocity distribution and spatial vortices system will be analyzed in this study. The UVH spray flow field numerical model will be built and calculated based on Lagrange discrete phase method, the influence act on droplet deposition and drift trajectory from operation parameters, ambient air flows and droplet diameter will be researched through the flow simulation deposition experiment. Research the droplet deposition patterns under different operation parameters and ambient air flows, the multi variable relationship model between operation parameters, ambient air flows and drift will be studied and built. The multi variable relationship model will be verified and corrected through field trial research, this study will be useful for the operation parameter selection and decision before the UVH field operation.

植保旋翼无人机喷雾施药技术是我国植保机械领域发展的重要方向，开展无人机田间喷雾的沉积规律研究可以促进我国航空植保喷雾技术的创新和提升。本项目拟采用模拟风场试验、数值模拟和田间试验结合的方法，研究旋翼无人机喷雾作业的雾滴沉积和沉降轨迹规律；通过设计搭建无人机喷雾模拟风场试验系统，以及旋翼流场CFD数值模型的构建、适用性和验证研究，深入分析旋翼流场的速度和空间涡系的变化规律；构建旋翼无人机喷雾场的气-液离散相数值模型，开展无人机喷雾的模拟风场沉积试验研究，量化解析作业参数、环境气流和雾滴粒径对喷雾沉积和沉降轨迹的影响规律，建立作业参数、环境气流与喷雾飘移之间的多变量关系模型；开展田间试验研究，对多变量关系模型进行检验和参数修正，为植保旋翼无人机田间喷雾的关键作业参数选择和决策提供有效参考。

航空植保是现代植保技术和产业的主要发展方向，无人机的喷雾沉积均匀性和飘移是决定其施药品质和作业效率的关键环节。本项目利用计算流体力学数值分析和试验相结合的方法，开展了单旋翼无人机低空喷雾作业旋翼流场、喷雾流场和雾滴沉积规律的数值分析与试验验证研究，本项目构建了单旋翼无人机低空飞行作业的旋翼流场数值模型，分析了无人机旋翼流场空间流速分布规律，设计搭建了无人机试验系统，并通过旋翼流场试验对数值模型结果进行了验证。研究构建了单旋翼无人机喷雾气-液两相流数值模型，设计了多因素正交试验分析方案，详细分析了飞行作业参数、雾滴粒径和环境气流对于雾滴沉降轨迹、有效喷幅、均匀性和飘移损失的影响规律，建立了作业参数等因素与雾滴沉积均匀性和飘移损失系数之间的多变量关系模型。在前述数值分析基础上，本项目设计搭建了无人机低空喷雾沉积试验系统，开展了无人机雾滴沉积试验验证研究，详细比较分析了雾滴沉积试验和数值模型的相对沉积量分布曲线、变异系数和有效喷幅变化规律，并基于试验结果，建立了无人机飞行作业参数、雾滴粒径等因素与沉积均匀性之间的多变量关系模型，验证了其准确性。该研究成果可用于单旋翼无人机低空植保喷雾作业参数的选择和决策，同时也为单旋翼无人机植保喷雾系统的优化设计提供了参考。