COMBINED EXPERIMENTAL AND NUMERICAL INVESTIGATION OF FORMULAE FOR EROSION AND DEPOSITION OF COHESIVE SEDIMENTS

1 mTsonvCTIoxTIansport of fine cOhesive sedinds inevitably leads to the develoPment of sediment deposits inreservoirs or zones with small flow velocihes in lowland rivers. Such sediment dePosits often conshtUte aconsiderable ecological danger, as cOhesive sediInnts have the ability to bind POllutants like heavymetals, polycyclic aromatic hydrocrtons or chlorinated hydrocaIbons (F6f8iner, l989). In the case of anextreme hydraUlic event like a flood or a reservoir dePlehon, erosion of cone…

COMBINED EXPERIMENTAL AND NUMERICAL INVESTIGATION OF FORMULAE FOR EROSION AND DEPOSITION OF COHESIVE SEDIMENTS

In order to evaluate the validity of commonly used formulae describing erosion and deposition of cohesive sediments for their application within numerical simulations, a combined experimental and numerical investigation is earned out. An annular flume is used for experiments on erosion and deposition of reservoir muds. The results of these experiments serve as validation data for the formulae in consideration. For this validation, the experiments are reproduced within a numerical simulation, which consists of two parts: In a first step, the flow in the annular flume is simulated within a 3D large eddy simulation. The flow fields obtained in these simulations then serve as input for the second step, a decoupled 2DV simulation of erosion and deposition processes during the experiments. The investigated formulae are those of Partheniades and Parchure & Mehta concerning erosion and of Krone and Richardson & Zaki concerning deposition.