Abstract:

: The air-suction precision seeder for small seeds is a planting machine, characterized by precision, high efficiency, and ease of operation, that uses air suction technology to sow small grain seeds at set intervals and depths into the soil. However, the forced vibration, enhanced by the increase in the operating speed, affects the seeding accuracy of the seeder and limits the seeding efficiency. To study the influence of vibration conditions on the seed suction performance of the air-suction precision seeder, we developed a computational fluid dynamics–discrete element coupling method to construct a bidirectional fluid–solid coupling numerical simulation model of the seed suction process under vibration conditions. Within the range of operating speeds from 0.6 km/h to 8 km/h, we quantitatively studied the population movement under different vibration frequencies, vibration amplitudes, negative pressure values, and seeding disc speeds and verified the simulation model and its analysis results through bench tests. The numerical results show that the interaction between the vibration frequency, vibration amplitude, and negative pressure value has the most significant impact on the single-seed rate. In addition, via variance analysis and response surface analysis, the optimal range of negative pressure values for achieving high single-seed rates under different vibration frequencies (4~10 Hz), vibration amplitudes (3~7.5 mm), and seeding disc speeds (4~50 rpm) was determined. The results indicate that, rather than the higher the negative pressure value, the higher the seed suction rate, the optimal negative pressure value for achieving a high seed suction rate varies with the specific vibration frequencies and amplitudes.

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