The scour and deposition pattern around an abutment under constant discharge condition is calculated using a three dimensional (3D) Computational Fluid Dynamics (CFD) model. The Reynolds-Averaged Navier Stokes (RANS) equations are solved in three dimensions using a CFD model. The Level Set Method (LSM) is used for calculation of both free surface and bed topography. The two-equation turbulence model (k-ε and k-ω) is used to calculate the eddy viscosity in the RANS equations. The pressure term in the RANS equations on a staggered grid is modeled using the Chorin's projection method. The 5th order Weighted Essentially Non-Oscillatory (WENO) scheme discretizes the convective term of the RANS equations. The Kovacs and Parker and Dey formulations are used for the reduction in bed shear stress on the sloping bed. The model also used the sandslide algorithm which limits bed shear stress reduction during the erosion process. The numerical model solution is validated against experimental results collected at the Politecnico di Milano, Milan, Italy. Further, the numerical model is tested for performance by varying the grid sizes and key parameters like the space and time discretization schemes. The effect of varying bed porosity has been evaluated. Overall, the free surface is well represented in a realistic manner and bed topography is well predicted using the Level Set Method (LSM).

使用三维（3D）计算流体动力学（CFD）模型计算恒定排放条件下基台周围的冲刷和沉积方式。使用CFD模型在三个维度上求解雷诺平均Navier Stokes（RANS）方程。水平集方法（LSM）用于计算自由表面和床的地形。二方程湍流模型（k- ε和k- ω）用于计算RANS方程中的涡流粘度。使用Chorin投影方法对交错网格上的RANS方程中的压力项进行建模。五阶加权基本非振荡（WENO）方案离散化了RANS方程的对流项。Kovacs和Parker和Dey配方用于减少倾斜床上的床层剪切应力。该模型还使用了滑坡算法，该算法限制了侵蚀过程中地层剪切应力的减小。数值模型解决方案根据在意大利米兰的米兰理工大学收集的实验结果进行了验证。此外，通过更改网格大小和关键参数（如空间和时间离散方案）来测试数值模型的性能。已经评估了改变床孔隙率的影响。总体，