黏性对深水波列非线性演化的影响

Viscosity Effect on Nonlinear Evolution of Deep-Water Wave Trains

修正的四阶非线性薛定谔方程(m NLS)所建立的数值模型能有效模拟深水波列的非线性演化,但当演化距离较长时,需考虑黏性衰减作用。在m NLS方程的基础上添加一个黏性修正项,建立更加完善的数值模型。模拟边带扰动初始条件下深水波列的演化,并对该过程中谱成分能量的变化进行分析,进而研究水池宽度、载波波陡、载波频率和尺度因子对深水波列非线性演化能量衰减的影响。

A numerical wave model based on the modified fourth-order nonlinear Schrodinger equation （mNLS） is good for describing the evolution of deep-water wave envelope, however, viscous attenuation effect needs to be taken into account when evolution distance is relatively long. A viscous modifying term is added to the mNLS governing equations to construct an improved numerical model, which works better in simulating nonlinear evolution. The evolution of deep-water under the sideband disturbance conditions are simulated and the energy variation of spectral components is analyzed. The energy damping in the nonlinear evolution of deep-water wave trains is investigated through varying the parameters ： the pool width, the carrier wave steepness, the carrier wave frequency, and the scale factor.