Author(s): Georg Premstaller; Peter Rutschmann; Lehrstuhl Und Versuchsanstalt F. Ur
Linked Author(s): Peter Rutschmann
Keywords: Step-Pools; Submerged weirs; Steep Channels; Numerical Simulation; Unsteady Flow; Waves
Abstract: Stepped channels, spillways and step-pool systems are common means in hydraulic design. In mountainous regions stepped channels have established themselves in bederosion control. These structures are known to be susceptible to unsteady wave development. In this work, the hydraulic components of the problem are analysed. The differences between free and submerged structures in terms of wave development are pointed out. A three-dimensional numerical simulation tool is employed to analyse wave development. Numerical accuracy and diffusion are assessed for different meshes and simulations are carried out in step-pool systems with varying discharges using a suitable mesh. Mass-, momentum- and energy- balance are analysed in order to distinguish between three different flow regimes. Wave development is finally analysed using a representative configuration.