气吸振动式排种器种盘内种群运动的离散元分析  

Discrete Element Method Simulation of Seeds Motion in Vibrated Bed of Precision Vacuum Seeder

作　　者：李耀明[1] 赵湛[1] 陈进[2] 徐立章[1] 

机构地区：[1]江苏大学现代农业装备与技术省部共建教育部重点实验室,镇江212013 [2]江苏大学机械工程学院,镇江212013

出　　处：《农业机械学报》2009年第3期56-59,76,共5页Transactions of the Chinese Society for Agricultural Machinery

基　　金：高等学校博士学科点专项科研基金资助项目(20060299004);江苏大学现代农业装备与技术江苏省重点实验室开放基金资助项目(NZ200703)

摘　　要：根据离散元法的基本思想,采用线性弹簧-阻尼-滑动接触力学模型,编写Matlab模拟程序,分析了气吸振动式精密排种器振动种盘内种群的三维运动规律。为了描述籽粒离散分布程度,给出了体积膨胀系数的计算公式。结果表明,种盘作小幅高频振动,种群可以产生向上抛掷运动而有效分离;膨胀系数随着振动强度的增加而增大,随种层厚度的增加而减小。分析了摩擦因数和碰撞恢复系数对不同层厚种子膨胀系数的影响。在初始层厚参数hs≈3.8、振动强度kv=5.65时,种子具有理想的运动状态,通过性能试验得到排种器的吸种率达98%。A Matlab program based on the discrete element method was developed to simulate the seeds motion in a 3-D vibrated seeder bed.The mechanical interactions force between seeds and also between seeds and the bed were modeled by linear springs,dash-pots and friction sliders.The cubic expansion coefficient,H,was calculated to describe the discrete distribution level of seeds.The simulation results show that,the seeds are separated effectively while the bed vibrated with high frequency and small amplitude,H increases with the increasing vibration strength,kv,and decreases with the seeds initial thickness,hs.The influences of friction coefficient and recovery coefficient on H were analyzed.The ideal active state was obtained at hs≈3.8 and kv=5.65.The experimental results also show that the seeds pickup ratio is more than 98%.

关 键 词：精密排种器 种群三维运动 离散元法 数值模拟 性能试验 

分 类 号：S126[农业科学—农业基础科学] O347.7[理学—固体力学]