Coupled RecurDyn-EDEM simulation and experimental analysis of a precision fertilization device

With the continuous expansion of orchard planting area and fruit production in China, the problem of low precision in the application of powdered organic fertilizers has become increasingly prominent. To address this issue, a specialized grooved-wheel fertilizer discharge device for pit fertilization machines was designed and optimized in this study. A RecurDyn-EDEM coupled simulation model was established, in which the fertilizer application rate-defined as the ratio of fertilizer mass deposited at the pit bottom to the total discharged mass-was selected as the evaluation index. A Central Composite Design (CCD) was employed to develop a regression model and optimize both operational and structural parameters. Specifically, the dial plate speed and scraper inclination angle were chosen as key factors for optimization. The results indicated that the optimal parameters were a dial plate speed of 64.3 r/min and a scraper inclination angle of - 17.3°, under which the single application amount reached 637.98 g and the fertilizer application rate was 97.57%. The deviation between the bench test and the simulation under the optimal parameters was only 2.11%. This research, by integrating theoretical analysis, numerical simulation, and bench testing, provides a valuable reference for the innovative design of powdered organic fertilizer applicators in orchards of the hilly regions of Southwest China.