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Proposing Institution

Fachgebiet Hydromechanik, TUM
Project Manager

Prof. Dr. Michael Manhart
Arcissstr. 21
80333 München
We plan to perform numerical simulations of flows interacting with complex structures, such as flow in a river interacting with a bridge pier with and without a scour hole. In this project we use the method of Large Eddy Simulation to investigate the flow physics in detail. The results are being used to improve our current understanding of the flows considered and to develop models that describe the processes involved with reduced computational effort.We consider the case of sediment transport around a bridge pier in a sandy river bed. We focus on the flow when a so-called scour hole around a cylinder in non-cohesive sediment is developing. This case has a high practical importance for estimation of bridge safety under flood events. Current empirical formula to predict scour depth as a function of water depth, velocity and sediment properties show large uncertainties when applied to real-life cases. Our research aims at understanding, how the flow field can be best predicted, how it evolves with flow parameters and how it interacts with the sediment. We plan to perform massive simulations to resolve the smallest structures in the flow that are responsible to local interactions.In our simulations, we solve the spatially filtered Navier-Stokes equations which describe the conservation of mass and momentum on an infinitesimally small volume. We use a Finite-Volume method on a Cartesian grid. Complex geometries are described by a so-called Immersed Boundary condition. A local grid refinement can be achieved by hierarchically arranged overlapping zonal grids. By these techniques, an efficient solver has been developed that is highly scalable and flexible in terms of grid resolution and geometrical configuration.

Impressum, Conny Wendler