Scour due to a Falling Plane Jet: A Comprehensive Approach

Abstract

This paper presents a theoretically based procedure for predicting the local scour depth and shape downstream of rectangular falling jets induced by high hydraulic structures. This approach, based on a theoretical analysis with the support of laboratory evidence, represents a development in local scour investigations around dams, spillways, drop structures, and other similar hydraulic structures. The adopted methodology computes the equilibrium scour depth using a sediment equilibrium approach, starting from the analysis of the flow field along the scour. It is suitable for application to high drop structure design in alluvial rivers and has accuracy compatible with the engineering practices in this field. In this context, the effect of jet air entrainment on the maximum expected scour depth is highlighted, as well as the time for scour evolution.