基于EDEM的振动种盘中水稻种群运动规律研究

Analysis of Rice Seeds Motion on Vibrating Plate Using EDEM

基于离散元法的基本方法,采用Hertz-Mindlin接触模型,运用EDEM软件对气吸式精密播种机振动种盘中水稻种群运动进行模拟仿真。分析了不同频率、振幅、种层厚度对种群空间分布密度的影响。对仿真区域垂直于种盘方向进行均匀分层,得到不同时间种群在每一层的分布情况。仿真结果表明:种盘振动频率11～12 Hz、振幅12～13 mm、初始种层数3～5时,种群在振动种盘中的空间离散程度较为理想。在播种机试验台上进行试验验证,选取种盘振动频率、振幅、初始种层数、吸种距离为试验因素进行正交试验,得出振动频率为11 Hz、振幅为12 mm、初始种层数约为4、吸种距离为30 mm时吸种效果理想。

Rice seeds motion on a vibrating plate was simulated using discrete element method software EDEM.The mechanical interaction forces,both between seed and the plate and among the seeds were modeled by Hertz-Mindlin（no slip）.With the variation of vibration frequency,amplitude and seeds initial thickness,their effects on the seeds spatial distribution were analyzed.The simulation area was divided into uniform layers in vertical direction and the seeds spatial distribution in layers at different time was obtained.The simulation results showed that with the plate vibration frequency of 11~12 Hz,vibration amplitude of 12~13 mm and seeds initial layer number of 3~5,the ideal seeds spatial distribution which was beneficial to improve suction precision could be received.Plate vibration frequency,vibration amplitude,seeds initial thickness and sucking distance were selected as influencing factors,then orthogonal experiments were carried out on test-rig and results indicated that the precision suction ratio was greater than 93% with the plate vibration frequency of 11 Hz,vibration amplitude of 12 mm and seeds initial layer number of 4.