The study of breaking tidal bore on movable bed using the SPH method

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Pourya Omidvar, Pooyan Nikeghbali

Tuesday 30 june 2015

11:45 - 12:00h at Oceania (level 0)

Themes: (T) Sediment management and morphodynamics, (ST) River morphodynamics

Parallel session: 5B. Sediment - River

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Investigation of a breaking tidal bore is a challenging problem in river mouth as the flow flows upstream and significant bed erosion and scour take place under the bore while bed load are advected upstream with the tidal bore. In this work, we use Smoothed Particle Hydrodynamics (SPH) to model the breaking tidal bore on movable bed, where steady and uniform flow in a channel is blocked by a moving gate and afterwards the flow propagates towards upstream. Results are first presented to model the breaking bore on a flat bed, looking carefully at velocity and surface profiles, and compared with the data of Koch and Chanson (2005). The comparisons between the SPH results with the data of Koch and Chanson (2005) are in a good agreement. Second, the breaking bore is tested in a channel with movable bed and sediment is treated as a Bingham fluid. The results are compared with available experimental data (Khezri and Chanson, 2012) for a particle motion. Moreover, we show the morphology change of the bed under the breaking bore. In general SPH performs well and is superior in determining the free-surface location and bore velocity.