Research On2D Numerical Model Of Sediment Movement Based On Finite Volume Method

Movements of sediment in the estuarine and coastal area are more complicatedbecause of the combined effect of tidal current and waves, which is still the maintopic of numerical model of sediment.In this thesis, relevant research work of tidal numerical model is reviewed at first,together with interaction of waves and currents, sediment numerical model forwave-current coexisting condition. Then a numerical model of sediment movement(2DST) is established by adding wave factor in the2D tidal current module (2DTC)of COASTALTOOL, which is based on the finite volume method. Details of theresearch work are as below:(1) Data-read-in module is modified to read in wave and sediment data; Moduleto calculate derivation for quadrilateral elements is added to provide better adaptationto triangular-quadrilateral mixed mesh; Improvement is made for the calculation ofhigher order term based on the Smagorinsky turbulence model, which is introducedinto the equation to account for the turbulence effect. All the work makes thenumerical model to be more ready for calculation in various aspects.(2) The solution of governing equation for sediment transport is improved furtherby introducing bottom stress module of the Soulsby parametric equations into thenumerical model. The bottom shear stress model is testified and satisfactory result isobtained.(3) Under the assumed conditions of wave and current, the process of sedimentmovement and morphological process are simulated by two different formulas ofbottom stress and comparisons and analysis are performed for the calculation results.