水稻收获脱出物内圆筒筛分运动规律仿真研究

Simulation study on the motion laws of threshed rice through a cylinder sieve

文中采用离散单元法(Discrete Element Method,EDM)多球聚合自动填充精确构建南粳9108水稻收获脱出物各成分颗粒模型,并数值计算混合物在圆筒筛中的筛分过程。分析了圆筒筛转速、直径、孔径和倾角对混合物各成分运动规律的影响。仿真结果显示:圆筒筛孔径和倾角对各成分轴向平均速度、筛下籽粒分布、筛分清洁率、筛分损失率及筛分效率均有较大影响;圆筒筛转速对籽粒和瘪籽粒的轴向平均速度有较大影响;圆筒筛直径对籽粒和瘪籽粒的轴向平均速度、筛下籽粒分布均有较大影响。文中研究了混合物内圆筒筛分过程中的运动规律,为研制出适合小田块耕作的轻简型谷物联合收获机筛分系统提供了新的研究方法与合理的设计参考。

In this article,Discrete Element Metho(DEM)is adopted to build the accurate model of Nangeng NO.9108 threshed rice(grains,shriveled grains and short stalks)and calculate the grain mixture’s screening process in a cylinder sieve.The influence of the cylinder sieve’s rotation speed,diameter,aperture and inclination angle on the motion laws and screening characteristics of threshed rice is analyzed.The simulation results show that cylinder sieve’s aperture and inclination angle have great influence on the axial average velocity of each component and the grain distribution under the sieve;the cylinder sieve’s rotation speed has great influence on the axial average velocity of grains and shriveled grains;the cylinder sieve’s diameter has great influence on the axial average velocity of grains and shriveled grains as well as the grain distribution under the sieve.Thus,the motion law of mixtures through a cylinder sieve is explored.The results provide a new research method and reasonable design reference for the cylinder-sieve subsystem suitable for grain harvest.