分层流中潜艇共振激发内孤波的传播

Propagation of internal solitary waves excited by resonance with submarines in stratified fluids

当潜艇航速与内波各模态的水平波速相等时,在分层流中航行的潜艇将共振激发内孤波。研究潜艇内波的传播对探测水下运动的潜艇具有重要的军事应用价值。考虑色散效应和非线性效应的影响,建立了潜艇内波传播的非线性KdV数学模型,采用TH数值方法求解内波各模态的波函数,由已知的当地浮频率可计算非线性KdV数学模型中的色散系数和非线性系数。采用有限差分方法对KdV非线性模型进行数值仿真,研究潜艇激发内孤波的传播规律。研究结果表明,计算得到的内波传播相速度和内波幅值与实验测量得到的结果误差均小于20%,说明建立的KdV模型能有效描述潜艇激发的内孤波的传播。

When the speed of a submarine is equal to the horizontal wave velocity of internal waves,the submarine sailing in stratified fluids will resonate to excite internal solitary waves.Studying the propagation of submarine internal waves has an important military application value for detecting the underwater motions of submarines.With the influence of dispersion and nonlinear effects taken into consideration,a nonlinear KdV mathematical model of submarine internal wave propagation is established.TH numerical method is used to solve the wave function of different modes of internal waves.The dispersion coefficient and nonlinear coefficient in the nonlinear KdV mathematical model can be calculated from the known local buoyancy frequency.The finite difference method is used to calculate the nonlinear model of KdV,and the propagation law of solitary waves excited by submarines is studied.The results show that the errors between the calculated internal wave propagation phase velocity and amplitude and the experimental results are less than 20%,which indicates that the established KdV model can effectively describe the propagation of internal solitary waves excited by submarines.