Author(s): M. R. Soliman; Satoru Ushijima
Linked Author(s):
Keywords: Numerical modeling; Local scour; Shallow water equations; MACS; Unstructured collocated grid; Parallel computation
Abstract: A depth-averaged morphological model has been developed to calculate bed deformation in alluvial sand beds. This model is based on MACS algorithm with unstructured collocated grid using the distributed memory system to increase the computational efficiency. MACS algorithm is used to handle the model system, which includes a hydrodynamic module and a sediment transport module. The hydrodynamic module is based on the two-dimensional shallow water equations with parabolic eddy viscosity turbulence model. The sediment transport module is describing bed deformation, which assumed that scouring is taking place in the form of bed load transport and is modeled with a modified AshidaMichue formula. Flow and sediment transport are simulated using two different time scales while using parallel computation to shorten scouring prediction time. Numerical simulations are carried out and compared with two sets of experimental results: local scour downstream solid apron and local scour around bridge pier abutment, to demonstrate the model performance. Comparison between experimental and numerical simulation results shows reasonably good agreement from engineering point of view.
Year: 2012