Author(s): Quan T. Nguyen; Joost W.M. Kranenborg; Nicholas Dodd; Riccardo Briganti; Jebbe J. Van Der Werf; Pieter C. Roos; Fangfang Zhu
Linked Author(s):
Keywords: No Keywords
Abstract: This study improves the numerical modelling of the swash zone by addressing limitations of the hydrostatic pressure assumption used in numerical models that rely on the Non‑Linear Shallow Water Equations (NSWE). It highlights the importance of higher‑order non‑hydrostatic pressure terms associated with vertical accelerations occurring during wave run‑up and rundown. These terms are approximated using a depth‑averaged numerical model coupled with a log‑law‑based Bottom Boundary Layer (BBL) sub-model that analytically reconstructs the vertical structure of the flow. The approach retains the computational efficiency of NSWE models while capturing the essential physics of vertical accelerations. Validation against laboratory-based experiment and depth-resolving Reynolds Averaged Navier-Stokes (RANS)‑based Computational Fluid Dynamics (CFD) model shows analytically reconstructed vertical velocity is more accurate than that from the CFD model when compared to the measurements. The higher-order pressure terms involving accelerations in the vertical velocity are generally comparable with the ones estimated from the CFD model, especially in the backwash phase.
Year: 2026