The study described in this report was conducted at the Iowa Institute of Hydraulic Research for the Marley Company, Kansas City, Missouri. A 1:300 scale model of the tower and an inside fan for simulating the natural draft were provided by the company. The tests were performed in an air tunnel with a 5-foot octagonal test section. The model was mounted on a turn table, and a false floor was provided on the upstream side. All experiments were performed for the specified total-head loss across the grid section of about 22 velocity heads.
