Author(s): Kazuyuki Ota, Hajime Nakagawa, Hao Zhang
Linked Author(s): Kazuyuki Ota
Keywords: Large Eddy Simulation, bed-material load, Euler-Lagrange, spur-dyke, movable experiment
Abstract: This study develops a simulation model consisting of the LES (Large Eddy Simulation), VOF (Volume of Fluid), and practical Eulerian-Larangian approach allowing for resolving motion of flow and bed-material load around a partially permeable (i. e. , Bandal-like) spur dyke. The numerical model is applied and validated in the movable bed experiment around four Bandal-like structures. The simulation model well reproduces the scour depth and deposition height around a laboratory experiment of the Bandal-like structures. Furthermore, a comparison of simulation results is made between the Bandal-like and impermeable spur dykes. The coherent structure resolved in the LES shows that the lower opened portion in the Bandal-like structures helps to interrupt development of the HV (horseshoe vortex) which facilitates scour development. In addition, sediment transport simulation shows that the suspended load passing though the lower opened portion plays an important role in facilitating transportation and deposition of the suspended load. The present numerical approach gives possible physical reasons as to why the sediment is likely to deposit around the Bandal-like structure
Year: 2017