Experiments on Self-Aerated Flow in Open Channels

Measurements of distribution of air concentration in self-aerated flows are presented in this paper. The experiments were made in a rough channel of sand-grain type surface at various slopes and discharges, and the data were used as a basis for study of the mechanism of entrainment of air and to relate the air content and distribution to the characteristics of the flow. The analysis of the data shows that the air distribution can be adequately described by relationships based upon a simplified concept of turbulent transport and thus are functions of the flow characteristics. The maximum depth and the mean velocity are both shown to increase above those of a corresponding nonaerated flow.