Simulation and parameter optimization of seed metering device based on CFD-DEM

Improving the precision of mechanized seeding is the key breakthrough in vegetable planting, which can save cost and increase the efficiency of seeding. In order to improve the seeding performance of seed metering device, the computational fluid dynamics and discrete element method (CFD-DEM) coupling simulation technology was adopted to simulate the single factor performance of the seed metering device. Also, the movement characteristics of seeds under different suction nozzle structure and operation parameters were analyzed. In order to explore the best combination of parameters, the central composite design (CCD) was carried out by factoring the cone angle of suction nozzle, the angular velocity of seed plate, and the negative pressure and considering their effect on the two responses of the qualified index and the miss index. The variance analysis of the experimental results showed that the negative pressure had the most impact on the qualified index and the miss index, followed by cone angle of suction nozzle, and angular velocity of the seed plate. A parameterized mathematical model was then established to determine the parameter optimization region. Parameter optimization indicated that the qualified index of seeding was greater than 95% and the miss index was less than 2.5% at a cone angle of 50°, negative pressure in the range of 4.87-5.64 kPa, and an angular velocity in the range of 1.67-1.95 rad/s. The bench verification experiment further verified the accuracy of the parameter optimization results. The results of simulation and parameter optimization in this paper can provide reference for the development of seed metering device in the future.