气送式排种器输种管内种子速度耦合仿真测定与试验  

Simulation and Test of Seed Velocity Coupling in Seed Tube of Pneumutic Seed Metering Device

作　　者：李衍军[1] 刘瑞 刘春晓 刘立晶[1,4] LI Yanjun;LIU Rui;LIU Chunxiao;LIU Lijing(Chinese Academy of Agricultural Mechanization Sciences,Beijing 100083,China;College of Engineering,China Agricultural University,Beijing 100083,China;Labdalin Farm in Inner Mongolia,Hulunbuir 022250,China;State Key Laboratory of Soil Plant Machinery System Technology,Beijing 100083,China)

机构地区：[1]中国农业机械化科学研究院,北京100083 [2]中国农业大学工学院,北京100083 [3]内蒙古拉布大林农牧场,呼伦贝尔022250 [4]土壤植物机器系统技术国家重点实验室,北京100083

出　　处：《农业机械学报》2021年第4期54-61,133,共9页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家重点研发计划项目(2017YFD0700702)。

摘　　要：设计气流输送式排种系统时需确定种子速度,以小麦种子为试验对象,采用计算流体动力学和离散元耦合的方法在不同播种量与风速情况下对输种管内种子速度进行数值模拟。采用标准k-ε模型非稳态的Lagrangian耦合算法进行气固两相流耦合仿真,在台架试验中运用高速摄像技术对输种管内的种子运动过程进行图像采集,将采集的图像进行二值化、反色、差分、腐蚀去噪声等图像处理,根据种子面积与质心位置特征提取种子的移动距离,并计算得到种子实际运动速度。仿真模拟与试验表明,输种管内种子速度主要受风速影响,播种量对其影响很小;不同风速下输种管内种子速度仿真值与试验值的相对误差范围为4.28%~6.06%,相同位置处不同风速种子速度仿真值与试验值的相对误差范围为4.86%~5.70%,通过计算得到输种管内种子速度的修正系数平均值为0.95。基于气固两相流耦合的输种管内种子速度仿真具有较高的准确度,验证了基于EDEM-Fluent耦合仿真测定输种管内种子速度的可行性。For the design of the pneumatic conveyor type metering system,wheat seeds were taken as test object to provide a reference basis,and through the calculation on the fluid dynamics and the coupling of the discrete element method to make numerical simulation. The standard k-ε model of unsteady coupling Lagrangian algorithm coupling simulation was used to simulate the gas-solid two-phase flow. The highspeed camera technology was used to capture images of the seed movement process in the seed tube for the experiment. The collected image was processed by binaryzation,color inversion,differential and corrosion and processing. The seed movement distance was extracted according to the characteristics of the seed area and the position of the center of mass,and the actual movement speed of the seed was calculated. The simulation and test results showed that the seed velocity in the seed tube was mainly affected by the wind speed,but the seed application rate had little influence. The relative error range between the simulated and experimental values of seed velocity at different wind speeds was 4. 28% ~6. 06%,and the ratio of simulation test results to real test results was approximately constant,which was supposed to be due to the influence of seed sphericity on movement speed. The results showed that the correction coefficient of the seed velocity in the seed tube was 0. 95. Therefore,the simulation test of seed velocity through fluid solid coupling simulation had a high accuracy,which verified the feasibility of the method of measuring the seed velocity of the seed tube based on EDEM-Fluent gas-solid two-phase flow coupling simulation. The research can provide a new method for measuring the seed velocity in the seed tube.

关 键 词：气流输送式 排种系统 输种管 气固耦合 种子速度 数值模拟 

分 类 号：S223.2[农业科学—农业机械化工程]