Due to the multitude of scales present in realistic oceanic conditions, resolving the surface stress is computationally intensive, motivating modeling approaches. In this work, a dynamic wave drag model is developed for large eddy simulation (LES) to quantify the effects of multiscale dynamically rough surfaces on the atmospheric boundary layer. The waves are vertically unresolved, and the total drag due to the horizontally resolved portion of the wave spectrum is computed through a superposition of the force from each mode. As LES can only resolve the horizontal wind–wave interactions to the filter scale Δ, the effects of the horizontally unresolved, subfilter waves are modeled by specifying a roughness length scale characterizing the unresolved wave energy spectrum. This subfilter roughness is set proportional to the subfilter root mean square of the wave height distribution, and the constant of proportionality is evaluated dynamically during the simulation based on the assumption that the total drag force at the wave surface is independent of the filter scale. The dynamic approach is used to simulate the airflow over a spectrum of moving waves, and the results are validated against high-fidelity phase-resolved simulations. The dynamic approach combined with the wave spectrum drag model is then used to study flow through a fixed-bottom offshore wind farm array, equivalent to an infinite farm, with each turbine represented using an actuator disk model. The dynamic model accurately adapts to the changing velocity field and accurately predicts the mean velocity profiles and power produced from the offshore wind farm. Furthermore, the effect of the wind–wave interactions on the mean velocity profiles, power production, and kinetic energy budget is quantified.

中文翻译：

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真实海洋条件下海上风电场大涡模拟的动态壁建模方法

由于现实海洋条件中存在多种尺度，解决表面应力需要大量计算，因此需要采用建模方法。在这项工作中，开发了用于大涡模拟（LES）的动态波阻模型，以量化多尺度动态粗糙表面对大气边界层的影响。波在垂直方向上未解析，并且由于波谱的水平解析部分而产生的总阻力是通过每个模式的力的叠加来计算的。由于 LES 只能将水平风波相互作用解析为滤波器尺度 Δ，因此水平未解析的子滤波器波的影响是通过指定表征未解析波浪能量谱的粗糙度长度尺度来建模的。该子滤波器粗糙度设置为与波高分布的子滤波器均方根成比例，并且基于波表面的总阻力与滤波器尺度无关的假设，在模拟过程中动态评估比例常数。动态方法用于模拟一系列移动波上的气流，并根据高保真相位分辨模拟对结果进行验证。然后使用动态方法与波谱阻力模型相结合来研究通过固定底部海上风电场阵列的流动，相当于一个无限风电场，每个涡轮机都使用致动器盘模型表示。动态模型准确地适应不断变化的速度场，并准确预测平均速度剖面和海上风电场产生的功率。此外，还量化了风波相互作用对平均速度剖面、发电量和动能预算的影响。