A noncontact self-suction wheat shooting device for sustainable agriculture: A preliminary research

In this study, a noncontact self-suction wheat shooting device was developed through TRIZ theory to improve seed-filling performance and eliminate the contact between seed and device. A preliminary suction experiment was developed using FLUENT to simulate airflow velocity and evaluate the feasibility of self-suction performance of seeds. The DEM-CFD coupling simulation experiment was conducted to investigate the shooting performance. The simulation results showed the airflow velocity was over 6.5 m/s while rotational speed was more than 800 rpm, which could meet the seed-filling requirements. With the rotational speed increase, seed velocity and seed filling performance improves. On the contrary, a larger rotational speed and installation angle induced a higher CF (contact force). CF was significantly affected by rotational speed, window length and installation angle. The increasing window length resulted in the improvement of seed filling performance in a certain range. Meanwhile, the indicators of coefficient of variation for seeding uniformity (CVSU), coefficient of variation for seeding depth (CVSD) and seed damage rate (DR) were evaluated to investigate sowing performance of self-suction shooting device in validation experiment. Results from bench and field experiment showed the seed-filling and shooting performance of self-suction shooting device under optimized operation parameters could fully meet the sowing requirement of winter wheat in North China plain. The collision performance between seed and blades of optimized self-suction shooting device was superior to the mechanical one. In specific, CVSU, CVSD, ASD, ASS and seed germination rate of optimized self-suction shooting device were 11.3%, 8.7%, 31.0 m/s, 30.1 mm and 89.2%, respectively.