Author(s): Boris Huber
Linked Author(s):
Keywords: CFD-simulation; Sedimentation; Sediment entrainment
Abstract: The tributary reach of a major river in Austria branches off at an angle of 17°. When water in the main river rises, fine sediment and suspended load can be transported into the side branch which can lead to deposition of material in the side branch. Physical model tests were carried out at the Institute of Hydraulic Engineering, Vienna University of Technology, which showed, that the direction of flow near the ground differs significantly from the main flow direction: when the water level at the tailwater was raised, bottom-near flow in the main river turned towards the direction of the tributary reach. This paper presents the results of a CFD-simulation of that phenomenon, based on the physical model tests. The numerical simulation reproduced the observed turning of bottomnear flow very well and showed that this effect is mainly affected by the tailwater conditions in the experiment. With the use of the CFD-simulation, the reproduction of the downstream boundary condition was more realistic. Furthermore, suggestions for the improvement of the flow conditions were gained.
Year: 2007