关键词: 披碱草, DEMCFD, 气力式播种机, 分配器, 耦合

Abstract: To study the influence of distribution heads of different types of airblown seed drills on the seed metering performance of Elymus, the particle movement of distribution heads was numerically analyzed by Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD) coupling simulation method. In the gassolid coupling model, EDEM software was used to simulate the solid phase of Elymus particles, and Fluent software was used to describe the gas phase. Through studying the effects of upper convex cover, flat cover, and conical cover distribution heads on airflow pressure, particle collision, and particle movement characteristics, it was clear that conical cover had the highest energy consumption and the most particle collision times. Flat cover was the most energysaving, had the least collision times, and had the minimum damage done to forage seeds. It was found that the larger the reflection angle, the greater the radial velocity and the more times of particle collisions after particles collided with the top of the distribution head. As the static pressure at the distribution heads inlet increased, the fans energy increased accordingly. The seed metering performance of Elymus was tested on the planter equipped with a flat cover distribution head. The apiece row consistency variability coefficient of seeding quantity  was 4.83%, the stability variability coefficient of the full seeding quantity  was 3.97%, and the breaking ratio of the Elymus seeds  was 1.36%, all of which met the requirements of national standards. The simulation and test results provided an idea for the future design and optimization of the distribution head of the airblown seed drill.

Key words:  Elymus, DEMCDF, airblown seed drill, distribution head, coupling