Seed movement characteristics and filling performance of seed metering device for baby bok choy based on CFD-DEM approach

To investigate the movement characteristics and filling performance of seeds in the working process of seed metering device, the movement characteristics of seed A which successfully completed the seeding process and seed B that dropped in advance during the working process were studied based on computational fluid dynamics and discrete element method (CFD-DEM) coupling approach. The analysis of seed velocity, compressive force and position were found that the movement characteristics of the two types of seeds in the process of moving to the leftmost side of the seed plate were basically the same. During the movement from the leftmost side of the seed plate to the positive pressure zone, the velocity and compressive force of the seed change greatly. The process was relatively unstable, and seeds were prone to fall early. The effects of seed agitator's rotational speed and seed layer thickness on seed filling performance were studied by single factor simulation test. The results showed that the seed filling performance was better when the seed agitator's rotational speed and seed layer thickness were 3 rad/s and between 35 and 40 mm respectively. The research results provided a reference for improving the structure and seed filling performance of seed metering device.