Straight-Stream Nozzle Models to Support Aerial Applications

Maintaining operational efficiency while mitigating spray drift potential can be challenging, particularly with modern aircraft that are capable of higher airspeeds. One of the easiest and most effective tools for reducing off-target movement is increasing droplet size, which minimizes the fraction of spray volume containing smaller, drift-prone droplets. Proper nozzle selection and use is the first and most significant step toward improving overall spray characteristics. Two straight-stream nozzles typically used in fertilizer banding applications were evaluated for performance when used under aerial application conditions. Both nozzles generally resulted in similar droplet-size characteristics when operated under similar conditions, although the H1/4U nozzle tips resulted in slightly larger droplet-size distributions overall. The resulting droplet-size models were incorporated into a series of computer and smartphone-based user interfaces that allow for simple inputs of application conditions (i.e., airspeed, spray pressure, and orifice size), with the resulting droplet-size characteristics returned to the applicator. With the ever-increasing need for application efficiency through the use of higher airspeeds and the critical need to mitigate off-target damage through increased control over the placement of applied sprays, it is anticipated that these and other straight-stream nozzles will find increased use throughout the industry, making the availability of these models critical to ensuring successful applications.