泥质海床的黏弹塑性模型

Visco-elastic-plastic model for muddy seabeds

为研究波浪在泥质海床上的波高衰减,该文利用不可压缩流体的基本方程建立了波浪作用下水和底泥耦合运动的数值模型,模型能适应各种形式的底泥本构关系。控制方程组采用有限体积法求解,自由表面和水与泥层的界面采用VOF方法模拟。通过对比研究黏性模型和黏弹塑性模型对于底泥引起波浪衰减现象的有效性表明,当底泥密度较小时,黏性模型可以较好地模拟底泥引起的波浪衰减,但底泥密度较大时,其塑性特征不能忽视,采用更具一般性的黏弹塑性模型才能较好地反映波浪衰减的趋势。

A numerical model of the interaction between waves and a muddy seabed was developed to study wave attenuation by the muddy seabed. The governing equations for both the water and the mud were the continuity equation and the equation of motion for incompressible fluids. The water was treated as a Newtonian fluid. A viscous fluid model and a visco elastic-plastic model were used to describe the rheology of the seabed. The finite volume method was used to solve the governing equations, and both the free water surface and the interface between the water and the mud were tracked by the VOF method. Wave attenuation by the muddy seabed was investigated for various seabed densities. The viscous fluid model performs well for the low density mud, but when the mud density is relatively large the plasticity of the mud plays an important role in the wave attenuation. Thus, the visco-elastic plastic model should be used for the mud.