Analysis of Scour Characteristics in Presence of Aerated Crossing Jets

Abstract

Jets scour is a major topic in hydraulic engineering. It has to be carefully analysed in order to understand the mechanism and predict its geometry. The jets conf guration has a deep inf uence on the scour features. In the present paper the analysis was conducted in presence of two symmetric crossing jets, varying the discharge, the air content, the tailwater level in the downstream stilling basin, the angle between the jets and the vertical distance of the jets crossing point from the water surface, for different vertical jets angle. It was proven that the presence of the air in the jets deeply affects the scour morphology. The scour geometry was analysed and compared with the respective obtained in black water conditions. Useful practical relationships are proposed to estimate the main scour hole dimensions. The analysis was also extended to non-dimensional prof les and it was proved that the effect of air content on them is negligible.