Simulation and Experimental Study of a Split High-Speed Precision Seeding System

According to the agronomic requirements of cotton precision seeding, the researchers designed a split seeding system to achieve high-speed precision seeding on the membrane. The 3D models used in the simulation process were created using Solidworks. They used the built-in Flow Simulation plug-in in SolidWorks to simulate the flow field in the drum and to grasp the air velocity and pressure changes. The CFD-DEM (computational fluid dynamics and discrete element method) coupling method was used to simulate the positive pressure airflow to transport the seeds, so as to grasp the movement of the seeds in the seed tube. EDEM (engineering discrete element modeling) was used to simulate the seeding process of the hole seeder, to understand the movement speed and trajectory of the seeds inside the hole seeder, and to analyze the reasons for missed seeding and reseeding. A three-factor, five-stage quadratic rotation orthogonal combination test was designed using Design-expert 13.0 software. This test evaluates the performance of a split seeding system by establishing a response surface for the seed rate, using the hole seeder speed, negative pressure, and hole diameter as test factors. The optimal parameter combination is obtained by optimizing the regression equation, which is further verified by bench tests. Under the hole seeding speed of 47.98 r/min, the negative pressure of 1.96 kPa and the hole diameter of 3.5 mm, the precision seeding system achieved a single seed rate of 90.9% and a missed seed rate of 4.3%. The verification test results are consistent with the optimization results, which meet the agronomic requirements of high-speed precision film seeding. This research provides a better technical solution for the application development of a precision seeder.