Design and optimization of the seed feeding device with DEM-CFD coupling approach for rice and wheat

In order to achieve uniform and stable seed supply over a large sowing volume range of seed supplies in an air-assisted centralized metering system for rice and wheat, the study designed a seed supply unit with an equal-width inclined inlet based on the Venturi principle. The parameters of the seed feeding device were determined through theoretical calculation, and the DEM-CFD gas–solid coupling method was used to simulate and analyze the migration and motion characteristics of Japonica rice seed particles in the seed supply device with the average seed supply rate and seed flow rate as the experimental objectives. The following experimental factors were first optimized to show a good transport performance of seed feeding device for both indica rice and wheat seeds: the outlet height of the mixing section (36.19 mm), the angle of the inclined seed feeding section (53.41°), the height of the inclined seed feeding section (50 mm), the average velocity of the seed outlet (18.67 m/s), and the average mass flow rate of the seeds (682.20 g/s). The feasibility of the simulation model was then verified through bench tests, and the coefficient of variation for displacement stability and consistency of the three seeds were all below 1.5 % and 7.0 %, respectively. The relative error between the actual seed supply rate and the theoretical seed supply rate was all below 1.5 %. This study provides a reference for analyzing the seed motion characteristics inside the seed feeding device and optimizing the structural parameters.