【作者】 吕昊；

【导师】 于建群；

【作者基本信息】 吉林大学 ， 农业机械化工程， 2014， 博士

【摘要】 本文以两种不同结构的外槽轮式排肥器和四种复合颗粒肥料为研究对象；由排肥器的三维CAD模型，建立了排肥器的三维离散元法分析模型；采用球颗粒、四球组合椭球颗粒以及三维实体扫描与球组合的方法建立了肥料颗粒的分析模型，采用线性粘弹性模型计算颗粒之间及颗粒与排肥器之间的接触作用力，采用自主研制的三维离散元法软件AgriDEM分析了排肥器的工作过程及其性能；通过改变排肥器的CAD模型，还对不同结构和尺寸的排肥器进行了分析，同时将离散元法分析结果与EDEM软件仿真及排肥器的台架试验结果进行了对比，初步证明了采用离散元法分析外槽轮式排肥器的可行性和有效性，为外槽轮式排肥器的研究和优化设计建立了一种新方法，主要工作如下。1）根据离散元法仿真排肥器工作过程的需求，本文以四种肥料颗粒（北京生物1号肥料、大庆2号肥料、山东3号肥料、吉林4号肥料）为研究对象，通过实验测定了肥料颗粒的物理力学特性参数，并对其力学特性的影响因素进行了重点研究，包括肥料含水率、肥料颗粒密度、三轴尺寸、刚度系数、动/静摩擦系数、碰撞恢复系数、弹性模量等。然后对测定结果进行讨论和分析，为下一步应用离散元法分析时确定合适的参数提供依据。2）对基于离散元法的排肥器工作过程分析方法进行重点研究，以四种肥料颗粒及两种不同结构的排肥器为研究对象；通过采用三维扫描仪扫描肥料颗粒轮廓数据，建立了四种肥料基于三维扫描数据的手动填充颗粒模型，以及采用课题组研发的TDEM软件建立了肥料颗粒的自动填充颗粒模型；采用基于CAD模型的建模的方法，由外槽轮排肥器的三维Pro/ENGINEER实体模型，建立了其三维离散元法分析模型，研究了采用球颗粒组合方法，初步建立了非规则形状肥料颗粒的离散元法计算方法。3）进行了外槽轮排肥器实际工作过程的台架试验，以自主设计并研制的有机玻璃为材料的两种不同结构的外槽轮排肥器为试验对象，以北京生物1号、大庆2号、山东3号、吉林4号四种肥料为试验材料，以PSJ排种器性能试验台为试验设备，测试分析在四种排肥轴转速（31.24r/min、40.87r/min、50.63r/min、61.22r/min)、三种外槽轮工作长度（20mm、40mm、60mm）、三种排肥舌角度（15°、30°、45°）下外槽轮排肥器的排肥过程及对排肥量的影响；同时借助高速CCD摄像机，对外槽轮排肥器内肥料颗粒的运动过程进行实时拍摄，通过BLASTER’S MAS爆破运动分析软件进一步分析肥料颗粒在外槽轮排肥器内的运动规律，为后续工作离散元仿真结果对比提供数据参考。4）采用离散元法对外槽轮排肥器的工作过程进行仿真分析研究，以两种不同结构尺寸的外槽轮排肥器以及四种复合肥料（北京1号生物肥料、大庆2号肥料、山东3号肥料和吉林4号肥料）为研究对象，由排肥器的三维CAD模型建立了其三维离散元法分析模型，采用球颗粒和椭球颗粒建立了肥料颗粒的分析模型，采用线性粘弹性模型计算肥料颗粒之间及肥料颗粒与排肥器之间的接触作用力，采用自主研制的三维AgriDEM软件分析了排肥器的工作过程及其性能，通过改变排肥器的CAD模型，还对不同结构和尺寸的排肥器进行了分析，同时将离散元法分析结果与第4章外槽轮排肥器的台架试验结果进行对比分析，两者相近且变化趋势相同，初步证明了采用离散元法分析外槽轮式排肥器的可行性和有效性，为外槽轮式排肥器的研究和优化设计建立了一种新方法。更多还原

【Abstract】 By adopting two types of outer groove-wheel fertilizer apparatuses with differentstructures and four kinds of composite particle fertilizer as the research objects, thedissertation has developed a new approach for groove-wheel fertilizer apparatus analysis andoptimization design. Firstly, according to the three-dimensional CAD model of fertilizerapparatus, its three-dimensional discrete element method (DEM) analysis model is built.Using spherical particles, four ball ellipsoid particles and the method of three-dimensionalentity scan combining with balls, the fertilizer particle analysis model is established. Then,by using linear viscoelastic model, the contact forces between particle and particle or particleand fertilizer apparatus are calculated. Using self-designed three-dimensional AgriDEMsoftware, the working process and performance of fertilizer apparatus is analyzed. Further,by changing the CAD model of the device, fertilizer apparatus with different structures andsizes are analyzed. Meanwhile, the DEM results are compared with EDEM simulation andplatform test results. The results preliminarily proved the validity and effectiveness of DEManalysis. The specific work is as follows:1) According to the simulation requirement of fertilizer apparatus operation using DEM,the dissertation has chosen four different fertilizer particles (①Beijing,②Daqing,③Shandong,④Jilin) as the research objects. By experiments, the physical andmechanical characteristics of the fertilizer granules have been determined, and the influencefactors on the mechanical properties have been studied emphasisly, which include moisturecontent, fertilizer particle density, three axis sizes, stiffness coefficient, dynamic/staticfriction coefficients, crash recovery coefficient, and modulus of elasticity, etc. Then, themeasure results were discussed and analyzed to provide a basis for the appropriateparameters of DEM analysis in the next step.2) The working process of fertilizer apparatus based on DEM are studied emphasisly. Byadopting two types of outer groove-wheel fertilizer apparatuses with different structures andfour kinds of composite particle fertilizer as the research objects, using3D scanner to scanthe fertilizer particle profile data, four kinds of fertilizer manual filling particles model basedon3D scanning data were set up, meanwhile, the automatic filling particles model offertilizer particles were founded by the research group developed TDEM software. Adoptingthe modeling method of CAD and according to the Pro/ENGINEER solid model of thefertilizer apparatus, the three-dimensional DEM model was established. Take the sphericalparticles combination method, the DEM calculation method for irregular fertilizer particles have been initially established.3) By adopting two different self-designed outer groove-wheel fertilizer apparatus usingorganic glass, choosing four kinds of fertilizers (①Beijing,②Daqing,③Shandong,④Jilin)and using a PSJ seed meter performance test rig as the test equipment, the bench test foractual working process of the fertilizer apparatus is conducted. In the test, four differentfertilizer shaft speeds(31.24r/min,40.87r/min,50.63r/min), three outer groove-wheelworking lengths (20mm,40mm,60mm), three fertilizing tongue angles (15°,30°,45°) arechoose as the experimental conditions. The influence of fertilizer process on fertilizerconsumption quantity is analyzed. By the aid high-speed CCD camera, the real-time motorprocesses of the fertilizers are recorded. Then, through the BLASTER’s MAS, the movementrule of the fertilizer particles in fertilizer apparatus is examined further. The results provide adata reference for the following DEM analysis.4) Using DEM to simulate and analyze the working process of outer groove-wheelfertilizer apparatus. Two types of outer groove-wheel fertilizer apparatuses with differentstructures and four kinds of composite particle fertilizer (①Beijing,②Daqing,③Shandong,④Jilin) are chosen as the research objects. According to the three-dimensional CAD modelof fertilizer apparatus, the three-dimensional DEM analysis model is established. Usingspherical particles and ellipsoid particles, the analysis model of fertilizer particles isestablished. By using linear viscoelastic model, the contact forces between particle andparticle or particle and fertilizer apparatus are calculated. Using self-designedthree-dimensional AgriDEM software, the working process and performance of fertilizerapparatus is analyzed. Further, by changing the CAD model of the device, fertilizerapparatus with different structures and sizes are analyzed. Meanwhile, by the contrastiveanalysis of DEM results and experimental results in chapter4, it is found that they aresimilar and have the same variation trend, which preliminarily prove the feasibility andeffectiveness of DEM analysis applying to the fertilizer apparatus. Thus, the dissertation hasproposed a new approach for the study and optimization design of outer groove-wheelfertilizer apparatus.更多还原