水波与淤泥质底床相互作用数值模拟——基于滞后回路特征的淤泥体流变模型

应用一个滞后回路特征的半经验的淤泥体流变模型描述表面水波作用下底床软泥层的振荡运动，建立了表面水波与淤泥质底床相互作用的垂向二维耦合模型。在数值处理上，为提高数值格式对水－泥界面附近流动的分辨力，较好地再现界面附近速度梯度大的流动特点，采用垂向对数网格处理技巧。模型验证是通过计算水波波高衰减率和底床软泥体输移速度，并与有关的实验测量数据进行比较。

Numerical Modeling of Water Waves Interaction With Soft Mud Beds: Based on an Empirical Rheology Model Featured by Hysteresis Loop

On the basis of the semi-empirical rheology model of soft mud under such oscillatory external forces as water waves, a vertical 2-D numerical model is developed for simulating the interaction between surface water waves and underlying soft mud beds. The rheology model used is featured by remarkable hysteresis loops in the relationships of shear strain versus shear stress and the rate of shear strain versus shear stress and strong nonlinearity. A logarithmic grid from the water-mud interface in the vertical direction is employed for numerical treatment, which increases the resolution of the flow in the neighborhood of both sides of the interface, thus contributes to reproducing the characteristics of wave boundary. Model verifications are given through comparisons between the calculated and the measured bed mud mass transport velocities as well as the rate of decay of surface wave heights.