A new formulation of the spectral dissipation source term for wind-wave modeling

大多数风浪模型都采用谱能量平衡方程，包括三个强迫项、大气输入源项、共振非线性波浪相互作用项和破碎耗散项。许多研究人员致力于发展合理的输入源项和非线性波波相互作用的参数化方法。然而，由于观测波浪破碎和波浪-湍流相互作用的难度很大，风浪中的能量耗散率还没有得到很好的了解。本文通过测量对风浪演变起重要作用的大气输入源、风浪谱和风浪作用下的湍流速度分量，研究了湍流速度谱的相似性。利用实验结果和光谱饱和参数的思想，模拟了一个光谱耗散源项。在该模型中，假定能量耗散率与频率为f的轨道速度分量的3次方成正比，并使用新定义的谱饱和度来估计能量耗散率。结果表明，在平衡范围内的光谱耗散率与方向谱的3/2次方和频率的-3^&lt；rd&gt；次方成正比。

Most wind wave models have used the spectral energy balance equation including three forcing terms, atmospheric input source term, resonant nonlinear wave-wave interaction term and energy dissipation term by breaking. Many researchers have made extensive efforts to develop reasonable parameterizations of input source term and nonlinear wave-wave interaction. However, because of the extreme difficulties involved in observing wave breaking and wave-turbulence interactions, energy dissipation rate in wind waves has not been well understood. In the present study, atmospheric input sources, wind-wave spectra and turbulent velocity components under wind waves that played an important role to the wind wave evolution were measured to investigate the spectral similarity of turbulent velocities. A spectral dissipation source term was modeled by using the experimental results and the idea of spectral saturation parameter. In this model, energy dissipation rates were assumed to be proportional to the 3rd power of the orbital velocity components with frequency f and were evaluated by using the newly defined spectral saturation. As a result, spectral dissipation rates in the equilibrium range were shown to be proportional to the 3/2 power of the directional spectrum and the -3^<rd> power of the frequency.