Experimental study on pressure and aeration characteristics in stepped chute flows.

The free flow on the step surfaces has received much attention for its representative body type, flow structure, water-air two phase flow, cavitation, and many complex issues. The experiments about the time-averaged pressure and aeration concentration distribution on the step surface show that the vertical plane of steps will inevitably experience negative pressure, which must rely on adequate aeration concentration to avoid cavitation damage. However, the self-aerated flow at the head section has a relatively low aeration concentration, and the concentration of the entire steps decreases with the increasing of weir head, the minimum appears in the vicinity of the corner, and the location is close to the minimum pressure. Thus, it is necessary to set aerator in the upstream end of the step surfaces to avoid cavitation damage. [ABSTRACT FROM AUTHOR]