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ARS Home » Plains Area » College Station, Texas » Southern Plains Agricultural Research Center » Aerial Application Technology Research » Research » Publications at this Location » Publication #322018

Title: The effect of vortex generators on spray deposition and drift from an agricultural aircraft

item Martin, Daniel - Dan
item Latheef, Mohamed - Ab

Submitted to: Agricultural Engineering Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/7/2024
Publication Date: 6/12/2024
Citation: Martin, D.E., Latheef, M.A. 2024. The effect of vortex generators on spray deposition and drift from an agricultural aircraft. Agricultural Engineering Journal. 6:1683-1696.

Interpretive Summary: Off-target drift from agricultural spray applications is one of the biggest issues facing the aerial application industry. The EPA has recently instituted a program aimed at reducing off-target movement of spray by utilizing technologies proven to reduce drift. An aerodynamic device that traditionally has helped general aviation pilots have better control of their aircraft was investigated for its ability to improve spray deposition and reduce off-target drift from agricultural aircraft. Test results showed that it was able to reduce downwind deposits by as much as 61% and drift deposits by 46%. Aerial applicators may be able to use this technology to reduce off-target drift from agricultural spray applications and protect more cropland due to smaller buffer zones.

Technical Abstract: Vortex generators (VGs) attached to the leading edge of an agricultural aircraft are purported to control airflow over the upper surface of the wing by creating small vortices that delay boundary layer separation, thereby improving the performance of the aircraft. These devices are commercially-available for use in the agricultural aviation industry. The benefits attributed to VGs remain largely descriptive and anecdotal in nature without rigorous empirical assessment in the field. The intent of this study was to evaluate whether or not this aerodynamic device could improve deposition or reduce drift when mounted on an agricultural aircraft. Airborne drift and ground deposition was measured with monofilament lines and mylar cards, respectively. Deposits were expressed as percent of fluorometric response from a spectrofluorophotometer. There were 46 % fewer downwind drift deposits on monofilament lines when VGs were installed than when VGs were not installed. Whether VGs were installed on the aircraft or not was the predominant factor which influenced deposition on monofilament lines. Downwind deposits on Mylar cards placed on the ground at 3 different locations (5, 10 and 20 m) varied significantly (P < 0.0001) between treatments with corresponding 31, 54 and 61% reductions in downwind deposits when VGs were installed. These findings may help researchers better understand the role of vortex generators in the reduction of drift relative to aerially-applied pest control agents.