Numerical Modeling of the Three-Dimensional Wave-Induced Current Field

This paper showcases the results of three-dimensional numerical modeling of coastal zone hydrodynamics, based on a recently developed three-dimensional analytical model incorporating a three-dimensional formulation of radiation stress. The study examines the influence of cross-shore and alongshore bathymetric variability on hydrodynamic model results, focusing on internal volumetric current transport, bottom friction, free surface elevation, and velocity distributions. Using coastal zone cases with increasing complexity and wave datasets, we analyze differences between 2D and 3D model solutions, as well as theoretical calculations based on analytical solutions. Results indicate that in idealized, homogeneous bathymetric conditions, 2D and 3D models yield similar outputs. However, increased bathymetric complexity introduces significant variations, particularly in velocity fields and transport dynamics. Alongshore variability further modifies these distributions, emphasizing the role of lateral gradients often neglected in simplified models. The study demonstrates that neglecting alongshore bathymetric heterogeneity can lead to underestimation of key hydrodynamic variables, affecting model accuracy in coastal applications. Two-dimensional current transport fields reveal circulation patterns and possible rip current formations, suggesting that the proposed model framework provides improved insights into real-world coastal hydrodynamics. These findings highlight the necessity of incorporating three-dimensional bathymetric variability in predictive models to enhance accuracy in coastal engineering and environmental management applications.