DEM-CFD investigation of particle motion characteristic in a guidance restraint-airflow blowing seed guiding device

Abstract

Sowing uniformity is critical to the quality of maize growth and yield. The performance of the seed guiding is key to determining sowing uniformity. In this work, a guidance restraint-airflow blowing seed guiding device was investigated using the coupled CFD and DEM approach. The study analyzed the effect of variables related to the seed-guiding device on the particle motion characteristics. The results showed that for the B-type guiding restraint segment, allowing seeds to quickly enter the seed guiding device at the same position, thereby providing an orderly seed flow for the subsequent airflow to effectively guide the seeds. The contraction port height is large and the stable acceleration segment length is small, the airflow has poor restraining ability on the seeds’ movement, making them prone to collision and bouncing. Subsequently, the seed guiding performance of the guided restraint-airflow blowing seed guiding device was verified. The results showed that the uniformity of grain spacing was good, meeting the requirements for precision maize sowing. In specific, the seed spacing coefficient of variation (SSCV) and average seed spacing (ASS) were 8.9 % and 24.5 cm at the height of the shrinkage port, length of the stable acceleration section and guiding restraint segment structure were 5 mm, 100 mm and B-type.