基于拟层流风波生成机制的海浪谱模型

An ocean wave spectrum model based on quasi-laminar wind-induced wave generation mechanism

海浪谱的能量可以视为由具有不同相速度的谐波携带的能量所组成。基于对风波形成、发展过程的认识,认为各组成谐波的能量由谐波自平均风摄取而来,由此根据拟层流模型推导出谐波能量密度的计算公式,建立以等效风速和峰值频率等为基本参数的海浪谱模型——随机Fourier函数模型,并给出了确定谐波频率、波长、相速度、振幅以及等效风速等模型参数的原则和计算方法。在59个实测样本谱基础上,采用随机建模方法确定模型参数的取值及其概率分布。结果表明,海浪谱模型可以很好地预测谱能,所计算的物理谱与实测谱均值吻合良好。

In this paper a wave spectrum is considered consisting of energy drawn from wind by a series of harmonic waves with differ- ent phase speeds. Based on this assumption, a stochastic Fourier function model is proposed, in which the equivalent wind speed and peak frequency are chosen as the basic parameters. The formulas of energy density transferred from wind to wave are derived in terms of the quasi-laminar model. The computation principles and methods for deriving the harmonic waveg frequency, wave length, phase ve- locity, wave amplitude and equivalent wind speed are introduced. Based on 59 recorded samples of ocean wave spectra, parameters of the stochastic Fourier function model are determined by the stochastic modeling principle. The simulation results indicate that the phys- ical model presented in this paper can estimate the spectrum energy well. The mean spectrum of the stochastic Fourier function and the power spectrum calculated by the theoretical model have a good agreement with records.