浮泥对非线性波的运动响应

KINEMATIC RESPONSE OF MUD LAYER TO SURFACE WAVES

将浮泥作为高黏度牛顿流体,与水体构成互不相混的两相流体,基于垂向二维RANS方程(Reynolds-averaged Navier--Stokes)、SST湍流模式(shear--stress transport),利用流体体积法(volume of fluid,VOF),结合数值造波、消波技术模拟波浪,建立了波--泥耦合运动的数学模型,研究了线性波、Stokes波和椭余波作用下,浮泥界面的运动响应.发现在各种波浪条件下,界面位移与表面位移间有相近的波形,两者间存在相位差,其值随周期和波高的变化不大;界面波高基本正比于表面波高,它随周期的增长呈单调增大的趋势.

A vertical two dimensional coupling model of air-water-mud system is established to investigate the response of mud-water interface to surface waves, in which the mud is considered as a Newtonian fluid with high viscosity and turbulence is modeled by means of the SST （shear-stress transport）. The VOF（volume of fluid） method is adopted to capture free surface, as well as mud-water interface. Different computational cases are considered according to five amplitudes and four periods of the surface wave to delineate the dependence of mud layer motion on the nonlinearity and the dispersivity of surface waves. The numerical results suggest that the mud-water interface undulates with the same wave length and period as the surface wave, albeit with a phase lead, which see^as independent of the surface wave height and period. The wave height of the mud-water interface is almost proportional to that of the surface wave, and tends to increase with the period.