  Numerical prediction of the interactions between wind and ocean waves is
essential for climate modeling and a wide range of offshore operations. Large
Eddy Simulation (LES) of the marine atmospheric boundary layer is a practical
numerical predictive tool but requires parameterization of surface fluxes at
the air-water interface. Current momentum flux parameterizations primarily use
wave-phase adapting computational grids, incurring high computational costs, or
use an equilibrium model based on Monin-Obukhov similarity theory for rough
surfaces that cannot resolve wave phase information. To include wave
phase-resolving physics at a cost similar to the equilibrium model, the Moving
Surface Drag (MOSD) model is introduced. It assumes ideal airflow over locally
piece-wise planar representations of moving water wave surfaces. Horizontally
unresolved interactions are still modeled using the equilibrium model.
Validation against experimental and numerical datasets with known monochromatic
waves demonstrates the robustness and accuracy of the model in representing
wave-induced impacts on mean velocity and Reynolds stress profiles. The model
is formulated to be applicable to a broad range of wave fields and its ability
to represent cross-swell and multiple wavelength cases is illustrated.
Additionally, the model is applied to LES of a laboratory-scale fixed-bottom
offshore wind turbine model, and the results are compared with wind tunnel
experimental data. The LES with the MOSD model shows good agreement in
wind-wave-wake interactions and phase-dependent physics at a low computational
cost. The model's simplicity and minimal computational needs make it valuable
for studying turbulent atmospheric-scale flows over the sea, particularly in
offshore wind energy research.
