ABSTRACT
Air flow through aerators has been measured on several built prototype structures. The most comprehensive set of measurements, including air flow through the side vents and the pressure variation under the nappe along the width of the chute, were for the Foz do Areia Spillway. The asymmetric case appears to indicate higher head losses for the air flow across the chute. However, other factors could possibly cause the near uniform pressure distribution, such as air being drawn through the water nappe. The first reported prototype measurements of air concentration, volume of air per unit volume, were for the Bratsk spillway. An attempt has been made to measure the air concentration at the floor of the spillway chute of Alicura spillway, 1985. Both the Bratsk and the Alicura data indicated a reduction of air concentration along the chute.
