PARAMETER OPTIMIZATION AND EXPERIMENT OF AN INSIDE-FILLING PNEUMATIC HIGH-SPEED PRECISION SEED-METERING DEVICE FOR COTTON

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.