荞麦米筛分物料接触参数测量与离散元仿真标定

荞麦剥壳后输出的主要混合物为荞麦米和荞麦,二者因尺寸差异较小造成分离困难。为了理清混合物分离中难筛物料的分离机理,拟借助EDEM软件对荞麦米筛分过程进行仿真,因仿真中所需筛分物料的接触参数无处查,需逐一确定,本文采用试验测定与EDEM仿真标定相结合的方法研究离散元仿真荞麦米筛分时所需的物料接触参数。试验测定了混合物各物料间、各物料与筛板间的碰撞恢复系数;混合物各物料间、各物料与筛板间的最大静摩擦因数,借助EDEM软件进行正交试验仿真标定以上各个参数。结果表明:离散元仿真标定的平均误差值小于7.90%,试验所测数据准确性较高,可为离散元仿真荞麦米筛分时物料接触参数设置提供参考。

The Measurement of Contact Parameters of Buckwheat Rice Screening Material and Discrete Element Simulation Calibration

The main mixtures after the shelled process of buckwheat are buckwheat rice and unshelled buckwheat. It is difficult to sieve them because they are similar in size. In order to find out the separation mechanism of the difficult screening material,the study intends to take advantage of EDEM software to simulate the sieving process of buckwheat rice. However,the contact parameters of the screening material in the simulation are nowhere to be found,thus they are needed to determine one by one. The study analyzes the contact parameters required for the discrete element simulation of buckwheat rice sieving by combining the experiment with the EDEM simulation calibration. The experiment measures the coefficient of restitution between different materials of the mixture as well as the coefficient of restitution between different materials and the sieve plate;the experiment also measures the coefficient of maximum static friction between different materials of the mixture as well as the coefficient of maximum static friction between different materials and the sieve plate,then using EDEM software to calibrate the above-mentioned parameters. The mean error value of discrete element simulation calibration is less than7. 90%,the result show that the accuracy of the experiment date is high,therefore,the experiment date can provide reference for the setting of material contact parameters for the discrete element method simulation of buckwheat rice screening.