Abstract:An air-assisted linear seed seeding device for wheat was created in order to address the issue that the pressure gradient’s change direction in the air-assisted seed seeding device is inconsistent with the direction of seed movement, leading to seed backflow or collision and decreasing the stability of grain spacing. To simulate the seeding process, a CFD-DEM unidirectional coupling simulation model was developed, which was based on the mathematical model of gas-solid two-phase flow. According to the simulation results, the length of the pipeline and the inlet pressure had a big impact on the flow field’s pressure distribution and overall pressure loss. The seeding device’s flow field had a uniform pressure distribution, and the direction of the pressure gradient change corresponded with the direction in which the seeds migrated.Wheat seeds followed a “straight-curve-straight line” motion path that avoided collisions and backflow. Inlet pressure, pipeline length, and operating speed were used as test factors in the response surface optimization test, and the grain distance variation coefficient served as the test evaluation index. The test findings indicated that inlet pressure, operating speed, and pipeline length were the primary and secondary factors influencing the grain distance variation coefficient. Operating speed and pipe length were influenced by inlet pressure. Through parameter optimization, the following parameters were found to be the best combinations: operation speed of 0.11m/s, pipeline length of 24.2cm, and inlet pressure of 5.1kPa.The soil tank test confirmed that under these conditions, the average grain spacing was 5.3cm and the coefficient of grain spacing variation was 6.3%, meeting the agronomic requirements for precise, uniform wheat sowing. By addressing the issues of wheat seed backflow and collision, air-assisted linear seeding may greatly enhance seeding performance and offer technical assistance for accurate and consistent wheat sowing.
