POULTRY A SIMULATION OF RELEASE HEIGHT AND WIND SPEED EFFECTS FOR DRIFT MINIMIZATION

Abstract

The near-wake portion of the USDA Forest Service aerial application prediction model FSCBG is applied to asensitivity study of release height and wind speed, the most important factors, along with droplet size distribution, inassessing deposition and drift from aerial application. Building on extensive previous work, this study examines thepredictions by the near-wake Lagrangian trajectory model of drift fraction downwind of the edge of the field. Ten aircraftand four BCPC droplet size distributions are used to simulate a typical agricultural spraying scenario. Findings from thisstudy demonstrate the effects of varying release height and wind speed on downwind drift, the reduction of downwind driftwith larger droplets, and the inherent ability of certain aircraft type to reduce downwind drift more easily than others.Model results indicate that fixed-wing aircraft generate lower drift at lower release heights, that helicopters generatelower drift at higher release heights, and that biplanes exhibit greater drift potential than the other two aircraft types.