Theoretical and Experimental Foundations for Resource-Efficient Optimization of Sprinkler Irrigation Using a Low-Pressure Deflector Nozzle Under Arid Climate Conditions

This study presents the theoretical and experimental foundations forthe resource-efficient optimization of sprinkler irrigation using a low-pressuredeflector nozzle under arid climate conditions. Particular attention is given to waterdroplet motion, droplet formation mechanisms, and evaporation losses, consideringaerodynamic drag and the influence of external environmental factors.Water droplet motion was described using differential equations based onNewton’s second law, while droplet diameter was evaluated as a function of outletvelocity, nozzle orifice diameter, surface tension, and fluid density. Evaporationand wind drift losses were analyzed as functions of air temperature, relativehumidity, wind velocity, and droplet size, allowing assessment of their combinedimpact on irrigation efficiency.Theoretical predictions were validated through laboratory and laboratory–fieldexperiments. The results confirmed stable water discharge within the low-pressureoperating range and the formation of aerodynamically stable droplets withdiameters of 1.0–1.4 mm. This droplet size range was identified as optimal forlimiting evaporation and wind drift losses, with the relative reduction inevaporation exceeding 50% under optimal operating conditions. Irrigationuniformity was evaluated using the Christiansen coefficient, which reached highvalues, demonstrating compliance with agrotechnical requirements.Overall, the obtained results indicate that the proposed low-pressure deflectorsprinkler nozzle provides an effective water- and energy-efficient solution forreducing evaporation losses and improving the performance of sprinkler irrigationsystems operating in arid and semi-arid regions.