Authors

Abstract

To address the poor seeding effect of inside-filling pneumatic high-speed precision seed-metering device for cotton, Computational Fluid Dynamics (CFD) and Discrete Element Method–Computational Fluid Dynamics (DEM-CFD) approaches were employed for simulation and optimization. The CFD technique was applied to analyze the influence of key structural parameters of the negative-pressure air chamber on the adsorption performance of the suction holes, while the DEM-CFD approach was used to investigate the motion of cotton seeds inside the seed-metering device during the seed-throwing stage. Based on these analyses, the optimal combination of structural and performance parameters of the seed-metering device was obtained. The simulation-optimized parameters were then validated through bench tests, which showed that at a suction hole diameter of 3.1 mm, a forward speed of 2.33 m/s (8.4 km/h), and a negative pressure of 3,178 Pa, the evaluation indexes were optimal: 96.25% qualification index, 1.83% multiple sowing index, and 1.92% missed sowing index. Further high-speed adaptability test showed that when the forward speed was 1.67~3.33 m/s (6~12 km/h), the qualification index remained greater than 91%, and both the multiple and missed sowing index were less than 5%, meeting the agronomic requirements of high-speed precision seeding for cotton.

Abstract in Chinese

针对内充气力式棉花高速精量排种器排种效果不佳的问题，采用 CFD 和 DEM-CFD 仿真分析方法对其进行了 模拟与优化。利用 CFD 仿真分析了负压气室关键结构参数对吸孔吸附性能的影响，采用 DEM-CFD 气固耦合 方法探究了投种环节排种器内部棉花种子运动规律，并获得了排种器关键结构与性能参数最佳组合。仿真优化 后的参数经台架排种性能试验表明，当吸孔直径为 3.1 mm、前进速度为 2.33 m/s (8.4 km/h)、负压为 3178 Pa 时，其试验指标最优且为合格指数 96.25%，重播指数 1.83%，漏播指数 1.92%。进一步经高速适应性试验表 明，当前进速度为 1.67~3.33 m/s (6~12 km/h) 时，合格指数均大于 91%，重播与漏播指数均小于 5%，满足 棉花高速精播农艺要求。