基于EDEM的窝眼轮式油菜排种器排种性能仿真与试验

Simulation and verification on seeding performance of nest hole wheel seed-metering device based on EDEM

【目的】研究不同型孔结构对窝眼轮式油菜排种器种子群扰动及排种性能的影响。【方法】借助离散元分析软件EDEM对3种不同型孔结构的窝眼轮式油菜排种器进行仿真分析,并进行试验验证。【结果】型孔结构对种子群扰动影响明显,种子群扰动量越大充种性能越好;转速在10~50 r·min^(-1)时,种子群扰动最大的30°倒角窝眼轮合格指数为86.6%~95.8%,明显优于不倒角窝眼轮的67.5%~90.6%和半径1.25 mm倒圆角窝眼轮的79.2%~93.5%。各轮对比试验发现,相同转速下,种子群扰动量越大漏播指数越小,型孔囊种空间大小因倒角方式而不同,且囊种空间越大,重播指数和变异系数也越大。【结论】影响各轮排种性能的主要因素是工作转速;由于重播指数较小,故合格指数主要受漏播指数影响;仿真与试验的结果有偏差,但变化趋势及其相互之间关系基本一致,用EDEM对排种器进行仿真分析具有一定可行性。

[ Objective ] To study the influence of different types of hole structures on the seeds interfer- ence intensity and seeding performance of nest hole wheel metering device for rapeseeds. [ Method ] The EDEM software was used to simulate the nest hole wheel with three different types of hole structures. Tests were also done to verify the simulation results. [ Result] Seeds interference intensity was affected by the hole structures evidently, and higher seeds interference intensity led to better seed-filling perform- ance. In aspect of qualified rate, the 30~ chamfering nest hole wheel （86. 6%-95.8% ） which had the largest seeds interference intensity performed much better than the nest hole wheel without chamfering （67.5%-90.6%） and the 1.25 mm rounded nest hole wheel （79.2%-93.5%） at 10 -50 r ~ rain-~ rotational speed. For different wheels at the same rotational speed, higher seeds interference intensity caused lower miss-seeding rate. The space of the type hole had a different size in each chamfering, and bigger space of the type hole caused higher miss-seeding rate and variable coefficient. [ Conclusion ] The main factor affecting seeding performance of each wheel is rotational speed. Since the redundant-seeding rate is low, the qualified rate is mainly affected by the miss-seeding rate. The fluctuation trends and the relationship among data are consistent in both simulation and test results, which proves the feasibility of the numerical simulation method based on EDEM.