Hydraulics & Waterways
398009 - 3D numerical simulation of local morphodynamics around complex in-stream structures
Thursday, June 7
8:30 AM - 10:00 AM
Location: Regency Room
In-stream structures are often designed for ecological and hydraulic purposes in stream restoration practice. The geometries of in-stream structures are typically very complex and irregular, for example, the engineered logs to mimic the large woody debris (LWD) in natural streams. This study is aimed to predict the sediment transport and bed morphological changes induced by the complex in-stream structures. The computational model, which couples the hydrodynamics and morphodynamics, is developed in OpenFOAM. The hydrodynamics part is flexible in the choice of turbulent models to capture the detailed local turbulent flows. The morphodynamics part uses an immersed boundary (IB) method to dynamically describe the geometrical deformation of the local river bed. The use of IBM eliminates the need of deforming the mesh, which is a very complex task and hinders the 3D scour modeling. A case study is presented to study the geomorphology around an engineered log jam (ELJ), which consists of multiple logs piled together. The numerical results of local turbulence and local morhphodynamics are compared with the experimental measurement in literature.