Author(s): Daniel B. Bung; Mario Oertel
Keywords: Stepped spillway; Non-aerated flow region; Physical modeling; Numerical simulation; Surface roughness
Abstract: Self-aeration on steep chutes sets in when the growing turbulent boundary layer reaches the free surface. While boundary layer growth is a function of surface roughness for given discharge and slope on a smooth invert chute, step-induced macro-roughness becomes significant on a stepped chute in skimming flow and surface roughness is generally neglected. In this study, effects of an artificial roughness with different configurations on non-aerated, developing flow are investigated on stepped spillway models. It is shown that the setup has different effects on velocities and flow depths on the structure.