Session: 06-16-01 Wave Mechanics, Modeling and Wave Effects - I

Submission Number: 179560

Experimental Study and Numerical Comparison of Turbulence Models for Phase-Focused Wave Breaking 

High-frequency wave attenuation and energy dissipation remain challenging to model the wave-breaking process in both numerical and physical simulations. Turbulence modelling of the energy dissipation is particularly difficult for broadband, high-frequency sea states. In this study, physical wave tests were carried out for phase-focused breaking and non-breaking waves generated from a range of sea-state spectra. A logarithmic zeroth moment is proposed to quantify energy distribution on a logarithmic frequency scale, and its influence on wave attenuation and dissipation is examined. Several turbulence models were evaluated including Large-Eddy Simulation (LES), Reynolds-Averaged Navier–Stokes (RANS), and laminar flow cases. The surface elevation, breaking position, and the geometric and kinematic characteristics of wave breaking were analysed together with the associated spectral properties. Results show that the widely used standard k–ε and k–ω SST models struggle to capture turbulent energy under high-frequency wave interactions, where turbulent viscosity (νₜ) plays a dominant role in numerical wave dissipation. The models are sensitive to empirically prescribed initial values, leading to under-prediction of surface elevation and inaccurate representation of wave breaking. In contrast, the LES approach performs well in reproducing nonlinear wave interactions and the associated energy-dissipation processes, without inducing a significantly higher computational cost, given the already demanding spatial and temporal resolution required for wave-breaking simulations. The findings provide insights into the understanding of wave-breaking dynamics and the improvement of the turbulence modelling.

Presenting Author: Lige Zhao University of Plymouth

Presenting Author Biography: ige Zhao is a PhD student at the University of Plymouth. Her research focuses on the experimental and numerical investigation of wave–structure interaction, particularly the wave-breaking behaviour around floating offshore wind turbines.

Authors:

Lige Zhao University of Plymouth
Alistair Borthwick University of Plymouth
Deborah Greaves University of Plymouth