Optimization and numerical simulation of the internal flow field of water–pesticide integrated microsprinklers

Abstract

AbstractA new type of water–pesticide integrated microsprinkler has been developed in this study. Microsprinklers can irrigate crop roots to meet the irrigation index demand under low‐pressure conditions and apply pesticides on the backs of crop leaves to meet the spraying pesticide index demand under medium‐pressure conditions. In this paper, the structure and working principle of the water–pesticide integrated microsprinkler are discussed, and the key structural parameters are the number and diameter of the small round holes and the number and width of bevel grooves. Computational fluid dynamics (CFD) numerical simulations were performed to analyse the influence and variation in the key structural parameters on the microsprinkler flow field. The optimized structural parameters of the microsprinkler were determined: The outlet nozzle diameter was 3 mm, with three small round holes of 2 mm diameter and three bevel grooves of 0.8 mm width. The hydraulic performance of the optimized sprinkler and original sprinkler (outlet nozzle diameter was 2.5 mm, with two small round holes of 3 mm diameter and four bevel grooves of 1 mm width) were compared under different working pressure conditions. The results showed that the wetted radius and uniformity coefficient of the optimized sprinkler increased by 23% and 16%, respectively.