Manifestation of spurious currents and interface regularization in wind turbulence over fast-propagating waves

TL;DR

This paper investigates how numerical errors like spurious currents and interface regularization affect wind turbulence simulations over fast-moving waves, emphasizing the importance of accurate interface treatment for reliable results.

Contribution

It systematically evaluates interface-capturing techniques and identifies key numerical error mechanisms impacting high wave-age wind-wave simulations.

Findings

Numerical errors can reach magnitudes comparable to physical flow in high wave-age regimes.

Spurious currents and interface regularization significantly influence turbulence statistics.

Accurate curvature and flux discretization are crucial for reliable wind-wave modeling.

Abstract

Accurate simulation of wind turbulence over fast-propagating waves requires interface-capturing methods that suppress numerical artifacts while accurately resolving momentum transfer across the interface. In high wave-age regimes, numerical errors at the air-water interface can reach magnitudes comparable to the physical flow, directly affecting predicted turbulence statistics. This study examines widely used interface-capturing techniques to evaluate how spurious currents and interface regularization influence wind-wave simulations through curvature estimation and flux discretization. A systematic assessment is performed using static and translating droplet benchmarks, together with solitary and monochromatic wave cases, to identify and quantify the dominant numerical error mechanisms. In addition, comparison with experimental measurements reveals how these primary error sources manifest in coupled wind-wave simulations. These findings clarify the numerical origin of the observed discrepancies and underscore the importance of accurate curvature and flux treatment in high wave-age regimes.