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| Research and application of three-dimensional numerical model of local scour based on finite volume method |
| Received:June 24, 2019 Revised:August 31, 2019 |
| View Full Text View/Add Comment Download reader |
| DOI：10.7511/jslx20190624001 |
| KeyWord:finite volume method local scour 3d numerical model circular pile spur dike |
| Author | Institution |
| 李登松 |
四川农业大学 水利水电学院, 雅安 |
| 戴光清 |
四川大学 水力学与山区河流开发保护国家重点实验室, 成都 |
| 金鑫 |
成都理工大学 能源学院, 成都 |
| 曾赟 |
四川农业大学 水利水电学院, 雅安 |
| 漆力健 |
四川农业大学 水利水电学院, 雅安 |
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| Abstract: |
| The destruction mechanism and degree of local scour can be predicted by a 3d numerical simulation and then more reasonable engineering prevention measures can be adopted to mitigate or avoid destruction of a structure.In this paper,the 3d numerical model of a local scour including the hydrodynamic model,the equations of sediment erosion and bed deformation were constructed based on the finite volume method and the unstructured grid.The turbulence model in the hydrodynamic model is the shear stress transport SST k-ω model.Building of the sediment erosion and deposition equation is based on the size and distribution of the bed shear stress.The coupling of the hydrodynamic and sediment model is one-way coupled.After the hydrodynamic model was calculated by ANSYS-FLUENT software,the hydraulic data including velocity and the shear stress would be transmitted to the equation of sediment erosion and bed deformation.The numerical calculation of the sediment erosion and bed deformation equation was achieved by User Define Function.Deformation mesh created by the updating of riverbed topography was reconstructed by the dynamic mesh technique.The numerical results are compared with the experiment of a local scour around the cylinder by Sumer and the experiment of local scour around the spur dike by Michiue to verify the reliability.The results of the scour depth and the flow characteristics in the scour pit at the moment of scour equilibrium show that the numerical model successfully simulates the final scour topography and morphology,and captures the three-dimensional terrain changes at different moments.The main conclusions were drawn from the analysis of the application of a numerical model.The model developed on the basis of the shear stress has the advantages of simple operation and strong reliability.Besides,the sediment flux reconstruction and bed slope would affect the accuracy of the model.Although the small deformation grids can be better reconstructed by the moving grid technology provided by FLUENT software,the large deformation grids caused by terrain changes would be difficult to reconstruct. |
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