波流作用下大尺度圆柱周围局部冲刷深度简化数值模型

利用数模研究了波流共同作用下大尺度孤立圆柱周围的局部冲刷问题．该数模包括波浪场模型、流场模型、剪应力模型和冲淤形态模型．在数值计算中，通过分别求解缓坡方程和浅水环流方程得到波浪场和流场的分布情况，据此计算出水质点的底流速，得到底床剪切应力场的分布情况．可通过底面剪应力与泥沙起动应力的比较来调节底床的地形．计算了不同条件下孤立圆柱附近的局部冲刷情况，据此研究了波高、流速对局部冲刷的影响，发现最大冲刷深度随流速、波高的增大而增长．数模采用有限元方法，结果比较合理．

A simple numerical model of local scour depth around a large-scale circular cylinder due to combined wave-current action

The local scour around a large-scale vertical circular cylinder due to combined wave-current action is numerically studied. The numerical model is composed of wave field model, flow field model, shear stress model and scour-and-fill shape model. In the numerical analysis, the distribution of the wave field and current field is studied by solving the gentle slope and shallow water circulation equations. Then the bottom shear stress distribution is analyzed after getting the water particle velocity. Based on these results, the bottom land form is regulated by comparing the bottom shear stress and silt enabling stress. Calculations are carried out in different cases to research into the effect of the wave height, current velocity on the local scour depth. The maximum scour depth increases when the current velocity and wave height increase. The numerical model uses a finite element method, and the numerical results agree well with the measured data.