DEM Study of Seed Motion Model-Hole-Wheel Variable Seed Metering Device for Wheat

On the basis of the discrete element method (DEM), the movement of seed particles during the filling process of a wheat hole-wheel variable seed-metering device was numerically simulated. The impact of various model hole structures, filling postures, and vibration frequencies on the performance of filling was investigated. The results demonstrated that the average speed and filling posture of seeds varied significantly between models. The research demonstrated that the planter’s filling effect was greatly enhanced by raising the average seed population speed in the confined region. Wheat seeds can be filled in the “flat” and “side” postures because the type of hole is conducive to smooth seed filling and the seed in the type of hole is not readily lost owing to vibration. The seed-metering devices adapt well to a vibrational environment, and the vibration factor has no discernible effect on the seed metering rate. The model holes (e.g., inverted fin-shaped holes) with the highest seed filling rate in the simulation test are employed in the bench test to validate the simulation model. The seed rate range was 300–3200 g/min, while the frequency of vibration was 0–10 Hz. Results indicated that the coefficient of variation of the stability of the total seeding rate was less than 1.3%, that the seeding rate of each row was consistent, and that the coefficient of variation was less than 3%, demonstrating that the simulation model was accurate and met the requirements of wheat agronomic seeding.