Self-induced unsteady flow on pooled stepped chutes

Pooled stepped chutes are used to increase the energy dissipation compared to stepped chutes and cascades with horizontal and flat steps. Despite that fact this geometry causes the formation of unsteady flow thus the inflow is constant. Based on hydraulic model tests this paper presents data to calculate the parameters of the unsteady flow region (occurrence, wave heights and wave frequencies) from the geometric parameters (step height, depth of the pool) and discharge. The mechanism of wave development is explained.