连续分层环境中Suboff激发的自由面尾迹数值仿真

Numerical investigation of free surface wake excited by Suboff in continuously stratified fluid

水下航行体与水体的相互作用会在自由面形成特定的水动力尾迹。为了研究水动力尾迹的产生机理及其特征,本文采用非定常雷诺平均(Unsteady Reynolds-Averaged Naiver-Stokes,URANS)模型以及VOF(Volume of Fluid)方法对连续分层环境中全尺度Suboff激发的自由面尾迹进行数值仿真研究。首先,研究密度连续分层对自由面尾迹特征的影响。将连续分层环境中Suboff周围的流场结构以及自由面尾迹与单层液体环境中的结果进行了详细的比较。其次,对连续分层环境中不同潜深下自由面尾迹特征进行了研究。结果表明,在潜深为20 m,速度为30 kn时,自由面最大波高达3.35 m。随着潜深的增加,Suboff运动对自由面的扰动减弱,自由面尾迹的特征也变得更加微弱。

The interaction between underwater-vehicle and fluid will generate specific hydrodynamic wakes on the freesurface.In order to study the mechanism and characteristics of the hydrodynamic wake,unsteady Reynolds-Averaged Naiver-Stokes(URANS) model together with VOF(Volume of Fluid) method is adopted to simulate the free surface wake excited by the full-scale Suboff model in the continuously stratified fluid.Firstly,the effect of continuously stratified fluid on the characteristics of free surface wake is investigated.The flow structure and free surface wake in the continuously stratified and homogeneous fluid are compared in detail.Secondly,the wake characteristics under different depths in continuously stratified fluid are studied.When the diving depth is 20 m,the maximum wave height is up to 3.35 m.With the increase of the depth,the perturbation of the free surface caused by the Suboff becomes smaller.Consequently,the free surface wake becomes weaker.