DEM-CFD coupling simulation and optimization of an inside-filling air-blowing maize precision seed-metering device
DEM-CFD coupling simulation and optimization of an inside-filling air-blowing maize precision seed-metering device
复制标题
内充式气吹式玉米精量排种器DEM-CFD耦合仿真与优化
DOI：
10.1016/j.compag.2018.05.006
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发表时间：
2018-07-01
影响因子：
8.3
通讯作者：
Zhang, Tianliang
中科院分区：
文献类型：
--
作者：
Han, Dandan;Zhang, Dongxing;Zhang, Tianliang
采用离散元法（DEM）与计算流体动力学（CFD）耦合的方法，对一种内充式气力式玉米精密排种器内的气固两相流进行了模拟。在该模型中，利用EDEM软件描述离散的颗粒相，使用ANSYS Fluent软件描述连续的气相。通过EDEM软件采用粘结颗粒模型（BPM）创建玉米颗粒，以定义颗粒的单一结构。从流场和种子运动方面对侧孔的位置、宽度和平均弧长的影响进行了检测和分析。采用正交试验设计，对影响排种器工作性能的最大评价指标的主次因素和参数进行了评估。确定了侧孔位置较低的优势，因为侧孔的宽度和平均弧长对曳力和压差均无影响。侧孔面积显著影响排种器孔内种子的运动和气流场。随着侧孔面积的增大，曳力、压差和压力损失增大，同时上部压力降低。优化后的侧孔在位置较低时，宽度为1.5 mm，平均弧长为10 mm，具有良好的工作性能，压力损失较小，曳力和压差性能优越。通过试验，当工作压力高于5.5 kPa且工作速度低于10 km/h时，优化后的排种器合格率大于93%。结果表明，DEM - CFD耦合方法是模拟种子在气流场中运动物理现象的可靠工具。种子运动的DEM - CFD耦合模拟可为评估内充式气力排种器潜在的工作性能提供理论依据。
Simulation of the gas-solid flow in an inside-filling air-blowing maize precision seed-metering device was performed by means of a coupling approach of the discrete element method (DEM) and computational fluid dynamics (CFD). In this model, EDEM software was used to depict the discrete particle phase, and ANSYS Fluent software was used to describe the continuous gas phase. Maize particles were created by EDEM software using the bonded particle model (BPM) to define a single structure of the particles. Effects of the positions, the width and the average arc length of the lateral hole were examined and analyzed in terms of gas field and seed movement. Using an orthogonal experimental design, the primary and secondary factors and parameters of the maximum evaluation index affecting the working performance of a seed-metering device were assessed. The superiority of a lower position of the lateral hole was identified, as both the width and the average arc length of the lateral hole had no effect on the drag force or differential pressure. The area of the lateral hole significantly affected the movement and airflow field of seeds in the hole of a seed-metering device. The drag force, the differential pressure and the pressure loss increase with the expansion of the area of the lateral hole also resulted in a decrease in the upper pressure. The optimized lateral hole, which is 1.5 mm wide and has an average arc length of 10 mm when the position is lower, had a good working performance, with less pressure loss, superior drag force and differential pressure. The qualified rate of the optimized seed-metering device was greater than 93% when the working pressure was above 5.5 kPa with a working speed lower than 10 km/h through experiment. The results showed that the DEM-CFD coupling approach was a reliable instrument for simulating the physical phenomenon of seed movement in the airflow field. DEM-CFD coupling simulation of seed movement can provide a theoretical basis for assessment of the potential working performance of an inside-filling air-blowing seed-metering device.