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Effects of typical corn kernel shapes on the forming of repose angle by DEM simulation

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International Journal of Agricultural and Biological Engineering 2022年第2期15卷 248-255页

作者： linrong shi Wuyun Zhao Xiaoping Yang College of Mechanical and Electrical Engineering Gansu Agricultural UniversityLanzhou 730070China

Corn kernel shape is an important feature to improve the accuracy of simulation results,also the repose angle is often used to calibrate model parameters in *** this study,the effects of the corn kernel shapes on the behavior during corn kernels accumulation were investigated in ***,the DEM models of three typical shapes of corn kernels were ***,the influences of the corn kernel shapes on the process of forming repose angle were investigated,such as corn kernels distance change,energy conversion,and the contact number between corn *** show that the corn kernel shape has a significant effect on the repose angle *** irregular shape of corn kernels limit their rolling when adding the corn kernel length in one or two *** addition,the irregular shapes of corn kernels increase the contact number and extend simulation *** shape corn kernels need to be mixed with irregular shape corn kernels to improve their ***,observation of the trajectory of corn kernel repose angles indicates that spherical corn kernels contact the bottom plate early,and forming small cone first,then the cone becomes bigger to change the direction of other corn kernels from top to bottom.

关键词： corn kernel shape energy conversion repose angle DEM

Determination of the coefficient of rolling friction of irregularly shaped maize particles by using discrete element method

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International Journal of Agricultural and Biological Engineering 2020年第2期13卷 15-25页

作者： linrong shi Wuyun Zhao Bugong Sun Wei Sun School of Mechanical and Electrical Engineering Gansu Agricultural UniversityLanzhou 730070China

The coefficient of rolling friction is a foundation parameter for conducting particles simulation,however,which of irregularly shaped maize seeds is difficult to ***,the coefficient of rolling friction between the simulation particles and the actual seeds is inconsistent due to the shaped difference of model and different position of gravity *** paper use two methods to determinate the coefficient of rolling friction based on discrete element method(DEM)and physical *** types of maize models from five different shaped maize samples(including horse-tooth shape,spherical cone shape,spherical shape,oblate shape,irregular shape)were developed with the help of slice modeling and 3D modeling *** cylinder container is used to arrange the simulation experiments of angle of repose with taking the coefficient of rolling friction as independent variables and the simulation angle of repose as target *** predicting detailed the coefficient of rolling friction(including horse-tooth shape,spherical cone shape,spherical shape,between horse-tooth shape and spherical cone shape,between horse-tooth shape and spherical shape,between spherical shape and spherical cone shape maize models),and forecasting a unified the coefficient of rolling friction among horse-tooth shape,spherical cone shape and spherical shape maize models,two types of materials(aluminum cylinder container and organic glass container)were used to validate the difference the angle of repose between the simulation maize models and actual maize *** show the relative error of the angle of repose between the maize models controlled by the coefficient of rolling friction through the detailed method and the actual maize seeds is 0.22%,0.33%in aluminum cylinder,organic glass container,*** relative error of the angle of repose between the simulation maize models controlled by the coefficient of rolling friction through the united method and a

关键词： coefficient of rolling friction maize irregularly shaped model angle of repose discrete element method

Analysis of the metering performance for typical shape maize seeds using DEM

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International Journal of Agricultural and Biological Engineering 2023年第1期16卷 26-35页

作者： linrong shi Wuyun Zhao Wei Sun Xiaoping Yang Guanping Wang Shanglong Xin College of Mechanical and Electrical Engineering Gansu Agricultural UniversityLanzhou 730070China

The irregular shape,varying internal compositions,and uneven distributions of maize seeds can degrade the metering performance of maize *** study investigates the effect of irregular maize on the performance of a high-filling-rate seed metering device using *** results show that the seed population in the seed box formed large and small cycles of seed transport due to the disturbances caused by the three *** increasing angular speed of the three wheels reduced the rate of seed filling in the seed filling regions by gravity and *** addition,an analysis of the repose angle formed by the dropped seed indicated that the angular speed of the taking seed wheel has a certain *** large angular speed reduced the coefficient of variation of the seed drop *** repose angle of the horse tooth seed was greater than those of the ***,the irregular maize seed can also reduce the coefficient of variation of the seed drop location.A comparison between the simulation and experiment results indicates the number of metering seed were basically the same.

关键词： maize seeds seed metering performance DEM verification

Determination and analysis of basic physical and contact mechanics parameters of quinoa seeds by DEM

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International Journal of Agricultural and Biological Engineering 2023年第5期16卷 35-43页

作者： linrong shi Wuyun Zhao Bugong Sun Wei Sun Gang Zhou College of Mechanical and Electrical Engineering Gansu Agricultural UniversityLanzhou 730070China Institute of Dryland Agriculture Gansu Academy of Agricultural SciencesLanzhou 730070China

Quinoa is an ancient crop that is nutritious,balanced,and suitable for most ***,it has not been known and sought by the public until modern *** recent years,quinoa has been intensively known and widely grown in *** mechanized production machines have also been *** the help of DEM,we design and optimize the quinoa combined seeder,improving seeding efficiency and *** this paper,the basic physical and contact mechanics parameters required for the Hertz-Mindlin(no slip)of quinoa seeds in EDEM software were *** coefficient of rolling friction of quinoa seeds was calibrated on DEM,and which of Long Quinoa 4 is 0.043,and that of Meng Quinoa 4 was ***,we can find that the coefficient of rolling friction strengthens the shape to restrict rolling and weakens the shape to increase *** above research provides simulation parameters for the design and optimization of quinoa seed seeding machinery.

关键词： quinoa seeds physical parameters contact parameters calibration DEM

Investigation of interaction effect between static and rolling friction of corn kernels on repose formation by DEM

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International Journal of Agricultural and Biological Engineering 2021年第5期14卷 238-246页

作者： linrong shi Xiaoping Yang Wuyun Zhao Wei Sun Guanping Wang Bugong Sun College of Mechanical and Electrical Engineering Gansu Agricultural UniversityLanzhou 730070China

The coefficient of static friction(SF),the coefficient of rolling friction(RF)for particles are two key parameters affecting the repose angle formation and flow *** this paper,the interaction effects of SF and RF on the formation process of corn repose angle was investigated by the discrete element ***,five shape kinds of corn models(horse tooth,spherical cone,spheroid,oblate,and irregular shape)were ***,aluminum cylinder and organic glass box were used to conduct the simulation experiments with taking SF and RF as independent factors and seeing the repose angle as dependent *** on simulation results the regression equations were *** results showed the relation between two factors and the rotational kinetic energy is not nonlinear,and SF does not significantly restrict the flow of corn models after increasing the flow direction,and the effect of SF on the contact number between corns and the bottom plate is remarkable,while the effect of RF on the contact number is not ***,the interaction effect of two factors on the repose angle was analyzed by variance analysis and results showed SF and RF all have a significant impact on the repose ***,their interaction effect has an impact on the repose angle.

关键词： corn kernels coefficient of static friction coefficient of rolling friction repose angle interaction influence

Potato planter test bed based on capacitive precision seed-monitoring and miss-seeding compensation system

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International Journal of Agricultural and Biological Engineering 2022年第6期15卷 104-112页

作者： Hua Zhang Wuyun Zhao Wei Sun Guanping Wang Xiaolong Liu Bin Feng linrong shi Yan Liu Hongling Li Mechanical and Electrical Engineering College Gansu Agricultural UniversityLanzhouGansu 730070China

Potato seed-monitoring is the premise of its precise ***,for anti-dust,anti-vibration performance and durability,the existing photoelectric monitoring schemes have obvious congenital ***,a capacitive precision seed-monitoring idea was proposed in this *** theoretical basis is that the variation of dielectric between the capacitor plates will inevitably induce the fluctuation of the detected capacitance ***,the construction of a space capacitance sensor,and the acquisition of the net capacitance fluctuation caused by the seed spoon passing through the space area of the capacitor plates,were the core focuses of this ***,the system theory and working principle were ***,a space capacitance sensor that meets all the requirements was analyzed and *** then,its spatial arrangement was described in detail,and most important of all,the technology roadmap of the net capacitance fluctuation measurement was put *** this purpose,MAX038 and GD32F407 were selected to work together to measure the *** this way,the top value of the space capacitance when a spoon passed through the space capacitance sensor was detected,at the same time,the corresponding grating encoder information was also recorded,so,the net capacitance fluctuation of this process was *** on this result,normal-seeding,miss-seeding,and multi-seeding were *** subtly,with the cooperation of the grating encoder,the position of the seed-metering monitoring point was configured *** for miss-seeding,a predictive impact compensation concept was *** on the theories above,the software core links related to seed-monitoring and compensation control were ***,a potato planter test bed based on this study was *** the Long-7 cutting potato as test samples,it was found that,the capacitance measurement error was no higher than 0.6%;no misjudgment on miss-seeding was found,however,for

关键词： potato planter capacitive precision seed-monitoring space capacitance sensor miss-seeding compensation system

基于离散元的西北旱区农田土壤颗粒接触模型和参数标定

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农业工程学报 2017年第21期33卷 181-187页

作者：石林榕赵武云孙伟甘肃农业大学机电工程学院兰州730070

为了解决利用离散元法模拟土壤作业过程在预测农具阻力和土壤动态运动时存在失真等问题,整合延迟弹性模型(hysteretic spring contact model,HSCM)和线性内聚力模型(liner cohesion model,LCM)优势建立西北旱区农田土壤模型,以不同参数... 详细信息

为了解决利用离散元法模拟土壤作业过程在预测农具阻力和土壤动态运动时存在失真等问题,整合延迟弹性模型(hysteretic spring contact model,HSCM)和线性内聚力模型(liner cohesion model,LCM)优势建立西北旱区农田土壤模型,以不同参数(静摩擦系数、动摩擦系数和内聚强度)组合下仿真得到的土壤仿真堆积角为响应值,基于Box-Behnken试验法建立回归模型,并根据该回归模型进行了参数预测并验证,对17组土壤仿真堆积角方差分析表明:静摩擦系数、动摩擦系数、动摩擦系数和抗剪强度的交互项、动摩擦系数的二次项对仿真堆积角的影响极显著;静摩擦系数和动摩擦系数的交互项、静摩擦系数的二次项对仿真堆积角的影响显著。使用预测的参数进行6种不同含水率土壤直接剪切仿真和试验对比可知,当含水率为1%~20%时,仿真与试验间的抗剪强度相对误差为1.18%~9.31%,仿真与试验间的内摩擦角相对误差为0.55%~4.07%。对仿真和试验鸭嘴插入阻力数据进行分析可知,仿真与试验曲线在入土距离处于0~50 mm期间时,但仿真入土阻力曲线波动较大,仿真和试验阻力走势基本一致,玉米直插穴播最深处50 mm处的仿真和试验入土阻力相对误差为0.928%,可利用此时的入土阻力分析直插鸭嘴结构对强度的影响。

关键词：土壤离散元法摩擦系数参数标定

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西北旱区玉米籽粒堆积和过筛试验

西北农业学报 2024年第9期33卷 1632-1640页

作者：韩进耀石林榕武威市凉州区农业机械化技术推广站甘肃武威733000 甘肃农业大学机电工程学院兰州730070

为了探究西北旱区主要种植玉米品种的堆积和过筛性能,设计及优化了玉米播种和收获装置,对4个玉米品种(‘三保黄金糯’‘东单509’‘大成168’‘铁杆吨玉’)进行参数测定、堆积和过筛试验。堆积试验结果表明,玉米在亚克力板上形成的堆积... 详细信息

为了探究西北旱区主要种植玉米品种的堆积和过筛性能,设计及优化了玉米播种和收获装置,对4个玉米品种(‘三保黄金糯’‘东单509’‘大成168’‘铁杆吨玉’)进行参数测定、堆积和过筛试验。堆积试验结果表明,玉米在亚克力板上形成的堆积角基本处于14~19°,在铁板上形成的堆积角基本处于18~21°;同一品种玉米在铁板上形成的堆积角比大于亚克力板。玉米过筛试验结果表明,玉米过筛率的大小与孔的大小呈正相关,‘三保黄金糯’玉米品种的过筛率最大,其次是‘东单509’‘大成168’和‘铁杆吨玉’。筛孔同尺寸条件下玉米籽粒在方孔筛板上过筛率要高于比圆孔;1号收集盒种子质量占比较大,为60%~80%。部分种子掉落2号收集盒,较少种子掉入3号收集盒,极少到进入4号收集盒。

关键词：玉米特征尺寸堆积角透筛率

玉米直插穴播机强排-强启排种装置设计与试验

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农业机械学报 2018年第2期49卷 41-47页

作者：石林榕赵武云杨小平孙步功孙伟甘肃农业大学机电工程学院兰州730070

在玉米直插穴播机的基础上,针对被动鸭嘴开启过程播种性能受地面高低起伏影响较大的问题,设计了强排-强启排种装置,主要由共轭凸轮、强排-强启排种器等组成。对前进速度补偿机构进行了分析,确定了穴播过程关键时间点,重点对强排-强启排... 详细信息

在玉米直插穴播机的基础上,针对被动鸭嘴开启过程播种性能受地面高低起伏影响较大的问题,设计了强排-强启排种装置,主要由共轭凸轮、强排-强启排种器等组成。对前进速度补偿机构进行了分析,确定了穴播过程关键时间点,重点对强排-强启排种器的取种轮取种和鸭嘴强制开启2个动作实现进行了位移计算,反求法计算确定共轭凸轮的主凸轮轮廓;取种轮匀速转动能提高取种率,通过计算确定了凸轮从动件运动规律。试验结果表明:该装置传动运行平稳,能完成取种和排种动作,鸭嘴无夹土、无提早排种现象;鸭嘴膜孔较小,鸭嘴播种期间无挑膜、撕膜等问题;玉米直插穴播机的空穴率为1.8%、穴粒数合格率为95.3%、膜下播种深度合格率为88.1%,设计的玉米直插穴播机强排-强启排种装置满足设计要求和玉米播种的农艺技术要求。

关键词：玉米直插穴播机排种装置共轭凸轮