Numerical simulation of the three-dimensional flow at the confluence of the Sava and Danube Rivers

Abstract

In this paper, the confluence hydrodynamics at the mouth of the Sava and Danube Rivers in the city of Belgrade is analysed by means of the three-dimensional numerical model. The confluence offers excellent possibilities for such investigation as the two morphological features typical for a river confluence are present: bed elevation discordance at the entrance to the confluence and the scour hole in the post-confluence channel. The results are discussed in terms of the secondary flow pattern. Since the non-defomble bed is assumed, the nature of the river bed - flow interaction is analysed in terms of a non-dimensional bed shear stress and a re-suspension number distributions for different flow conditions in the confluence.