非线性不规则波的数值模拟

根据波动方程得到了二阶非线性不规则波的模拟公式，以及二阶波谱的计算式； 探讨了有限水深不规则波的数值模拟方法。利用波浪槽中实测的波谱和理论谱分别计 算了二阶谱，并对不规则波时间序列进行了数值模拟．结果表明，二阶谱对实测谱的影 响主要发生在二倍谱峰频附近及低频区附近；二阶模拟对线性模拟有一定改善作用，

Numerical Simulation of Nonlinear Irregular Waves

The method for simulation of nonlinear irregular waves in water of finite depth is described. The solution to the wave equation correct to the second order is presented. The waye spectra measured in the laboratory are decomposed into the first order spectrum and the second spectrum in order to simulate time series of irregular waves in the finite depth. Both linear and nonlincar wave realizations are simulated from the measured and theoreticat spectra. The computed results show that the effect of the second order spectrum on the measurad spectrum is mainly in the vicinity of two-times peak frequency the spectrum,and that the second order simuation has made the improvement on the linear one in the estimation of wave height distribution.