基于离散单元法的高填充率窝眼轮式精密排种器排种仿真试验

Simulation test for nest-eye-wheel precision metering device with high fill rate based on the discrete element method

【目的】设计一种适应高速播种的高充填率精量排种器,确定该排种器的最佳排种性能参数(排种轮转速、排种轮与种刷及扰动滚筒的传动比、窝眼轮型孔圆角半径).【方法】采用离散单元法,建立3种不同大小的玉米模型,对高填充排种器进行了仿真模拟试验,观察分析玉米籽粒在排种器中的排种、重播、漏播的过程,确定最优参数,并进行试验验证.【结果】确定了排种轮转速为25r/min,窝眼轮圆角半径为1mm,排种轮与种刷和扰动滚筒之间的传动比为1∶2时排种性能最优,此时粒距合格指数为98.6%、重播指数为0.8%、漏播指数为0.6%、排种综合指数为98.9%,试验验证误差<5%.【结论】高填充率精量排种器可适用于高速播种,应用离散单元法优化排种器性能参数可减少实际工作量,为设计提供参考.

[Objective] To design a precision metering device with high-speed high filling rate of seeding, deter- mine the optimum performance parameters for it including wheel speed, the transmission ratio of the wheel to the brush and disturbing roller, fillet radius of wheel hole. [Method] Using discrete element method, three different size model of corn were established to carry out simulation tests, observe and analyze the process of seeding, reseeding, miss-seeding and determine the optimal parameters, and performed test verification. [Result] The test determined that the performance was optimal when the wheel speed was 25 r/min,the hole wheel radius at 1 mm, the trans- mission ratio of the wheel to the brush and the reduced pressure roller was 1：2, with the qualified index of grain space at 98. 6%, the reseeding index at 0. 8%, the miss-seeding index at 0. 6% and the comprehensive index of see＆metering at 98. 9% with test validation error less than 5%. [Conclusion] Precision seed-metering device with high filling rate can be applied to high-speed seeding. Optimizing the performance parameters using discrete element method could reduce the actual workload and provide reference for the design of the device.