ASSESSMENT OF AN AGRICULTURAL SPRAY IN A NON–UNIFORM CROSS–FLOW

摘要

Spray from an agricultural flat fan nozzle was studied in the presence of a non-uniform crosswind velocity profile in a wind tunnel to examine the size-velocity characteristics, the movement of the droplets in the wake of the spray pattern, and to define spray drift potential. The spray was generated at 275 kPa pressure in the presence of a 5 km/h mean crosswind. Size and velocity components of the droplets were measured in the central region of the spray at various downwind locations in a 1 × 0.3 m grid using a Phase-Doppler Particle Analyzer. The results indicate that droplets 100 µ m diameter were separated from large droplets and moved downwind in the horizontal direction. Some small droplets in the wake of the spray moved back towards the nozzle and were potentially carried for deposit. The majority of droplets 100 µ m were expected to deposit within 1.0 m from the nozzle axis, while droplets 100 µ m were expected to deposit within 0.3 m from the nozzle axis