On an eddy viscosity model for energetic deep-water surface gravity wave breaking

We present an investigation of the fundamental physical processes involved in deep-water gravity wave breaking. Our motivation is to identify underlying reason causing deficiency eddy viscosity breaking model (EVBM) predicting surface elevation for strongly nonlinear waves. Owing limitation experimental methods provision high-resolution flow information, we propose a numerical methodology by developing EVBM enclosed standalone fully quasi-potential (FNP) and coupled FNP plus Navier–Stokes model. The models were firstly verified with train subject modulational instability, then used simulate series broad-banded focusing trains under non-, moderate- strong-breaking conditions. A systematic analysis was carried out investigate discrepancies solutions produced two other important properties. It found that predicts accurately energy dissipated amplitude spectrum free waves terms magnitude, but fails capture induced phase shifting. shift grows intensity especially strong high-wavenumber components. This identified as cause upshift dispersion relation, which increases frequencies large-wavenumber Such variation drives components propagate at nearly same speed, significantly higher than linear levels. suppresses instant dispersive spreading harmonics after focal point, prolonging lifespan focused expanding their propagation space.