Photos by Gail Keck
Sid Gunasekaran, assistant professor of mechanical and aeronautical engineering at the University of Dayton, attaches this custom-made test section to the university’s wind tunnel to conduct agricultural spray drift studies. It takes about half an hour to roll the unit into the wind tunnel and set it up for operation.
As the wind tunnel pulls air from right to left through the test section, researchers photograph and measure the distribution of droplet sizes leaving the spray nozzle. The wire mesh filter at left removes the chemical droplets from the air.
When spray leaves the nozzle, a laser-based instrument is used to determine the size of the droplets.
A wire mesh filter captures water and chemicals used in spray tests. As they developed the wind tunnel test section, researchers pulled water colored with fluorescent dye through the wire mesh filter to make sure test chemicals would not be spread throughout the lab.
The spray tests use a constant wind speed of 15 mph to meet U.S. EPA standards. The UD wind tunnel can create wind speeds up to 90 mph and can also be set up to create turbulent winds using these louvers.