Abstract
With the sustainable development of precision agriculture, the valve regulated proportional fertigator has attracted research attention due to its high efficiency combined with low cost and incidence of damage. In order to investigate the hydraulic performance of the fertigator, the internal flow, force and motion of the piston were analysed by means of dynamic simulation and experimental validation. Results show that the inlet flow of fertilizer first increased and then decreased with the increase of the three-way valve angle under the same pressure conditions. The area with the highest flow velocity of 13 m/s in the fertigator concentrates on the inlet one-way valve and three-way valve part, while the fertilizer extraction part and the outlet part were in the low flow velocity area. The movement frequency increased with the increase of the threeway valve angle, except the middle part that showed variations in the wave change. With the increase of the inlet pressure, the variations in the three-way valve angles were also increased. At the initial stage of piston motion, the driving force was much greater than the resistance, and the driving force and the resistance fluctuated from the initial maximum to the same stable value. The resultant force of the piston fluctuates from the initial maximum driving force of 242 N to 0 N, and then the piston accelerates from 0 N to the minimum driving force of 8.5 N. When the resultant force was reduced, the acceleration also decreased. However, when the acceleration was reduced to zero (0), the piston started to move uniformly, which is useful for achieving consistency in the spread of fertilizer application in the artificially drained catchment. The maximum relative error between simulation and experiment was 15%. However, there was no difference in the overall trend, so we can draw a reasonable and accurate conclusion of the simulation. The study could be useful for achieving uniformity in the spread of fertilizer application in the artificially drained catchment.