论文标题
有限的非高斯性对随机风波进化的影响
Effects of finite non-gaussianity on evolution of a random wind wave field
论文作者
论文摘要
我们通过比较动态方程的动力学方程和直接数值模拟（DNS）的数值模拟来研究通过恒定强迫产生的随机风波场的长期演变。尽管光谱的积分特性在相当良好的一致性中，但光谱形状在很大程度上有很大差异，但DNS光谱形状与现场观测的一致性更好。在DNS数值方案中的共振数和大致共振波相互作用的数量变化时，我们表明，当哈密顿量的非线性和线性部分的比率趋于零时，DNS光谱形状接近动力学方程预测的形状。我们将动力学方程建模，一侧与DNS和观测值之间的差异归因于动力学方程的推导中非高斯性的忽视。
We examine long-term evolution of a random wind wave field generated by constant forcing, by comparing numerical simulations of the kinetic equation and direct numerical simulations (DNS) of the dynamical equations. While integral characteristics of spectra are in reasonably good agreement, the spectral shapes differ considerably at large times, the DNS spectral shape being in much better agreement with field observations. Varying the number of resonant and approximately resonant wave interactions in the DNS numerical scheme, we show that when the ratio of nonlinear and linear parts of the Hamiltonian tends to zero, the DNS spectral shape approaches the shape predicted by the kinetic equation. We attribute the discrepancies between the kinetic equation modelling, on one side, and the DNS and observations, on the other, to the neglect of non-gaussianity in the derivation of the kinetic equation.
