Parameters for the CFD simulation experiments.

To address the problem of poor fertilizer uniformity caused by vibration and skewing during rice transplanter operations, this study developed a pneumatic centralized spiral fertilizer discharge system. By leveraging the combined effects of high-speed swirling airflow and a spiral conveying pipe, the system generates a high-speed rotating air–fertilizer mixed flow, mitigating the negative effects of ground unevenness and machine vibration on fertilizer performance. Through multi-parameter coupled simulation experiments, the optimal working parameters for the spiral conveying pipe were identified as follows: a spiral pipe length of 444.35 mm, a cross-sectional slope angle of 26°, an airflow velocity of 35 m s−1, and a screw pitch of 105 mm, achieving a coefficient of variation of 4.61%. To simulate complex field environments, comparative bench experiments were conducted between the spiral conveying pipe and the smooth straight pipe. The results showed that, at inclination angles of 0°, 5°, 10°, and 15°, the coefficients of variation for the spiral conveying pipe were 4.53%, 5.87%, 8.47%, and 9.64%, respectively, significantly outperforming the smooth straight pipe. Compared to the smooth straight pipe, the spiral conveying pipe reduced the coefficients of variation by 50.81%, 54.07%, 44.53%, and 50.54%, respectively. Field experiments demonstrated that the coefficient of variation for the spiral conveying pipe was 5.27%, representing a 63.1% reduction compared to the 14.28% recorded for the smooth straight pipe. The results confirm the effectiveness of the spiral conveying pipe’s structural design and its superior fertilizer performance, making it highly suitable for complex paddy field environments.针对水稻插秧机作业过程中因振动与偏斜导致的施肥均匀性不佳问题，本研究研发了一种气动集中式螺旋排肥系统。该系统借助高速旋流与螺旋输送管的协同作用，产生高速旋转的气肥混合流，可削弱地面不平整与机械振动对施肥性能的负面影响。通过多参数耦合仿真试验，确定螺旋输送管的最优工作参数如下：螺旋管长度444.35 mm、截面倾斜角26°、气流速度35 m·s⁻¹、螺距105 mm，此时变异系数为4.61%。为模拟复杂田间环境，本研究开展了螺旋输送管与光滑直管的台架对比试验。试验结果表明，在倾斜角分别为0°、5°、10°、15°的工况下，螺旋输送管的变异系数依次为4.53%、5.87%、8.47%、9.64%，性能显著优于光滑直管。相较于光滑直管，螺旋输送管的变异系数分别降低了50.81%、54.07%、44.53%与50.54%。田间试验结果显示，螺旋输送管的变异系数为5.27%，相较于光滑直管测得的14.28%，降低了63.1%。上述结果验证了螺旋输送管结构设计的有效性与优异的施肥性能，使其极适配复杂稻田作业环境。