Hydrodynamic performances of vertical wall type breakwater with slotted barriers: a physical and numerical approach

Abstract

The present experimental investigation examines the surface gravity wave reflection and fluid force experienced by the vertical wall-type breakwater against the dimensionless water depth. The toe protection is provided and experimentally analyzed to secure the vertical caisson breakwater from the failures. Two types of barriers such as vertical slotted barrier (VSB), and horizontal slotted barrier (HSB) are installed and away from the vertical caisson breakwater to create a wave trapping chamber. The effect of barrier porosity varying from 10 to 50% on wave trapping and the scattering coefficients, i.e., pressure distribution, wave force, wave reflection, and wave runup, is reported. The integrity of the present study’s experimental results is ratified with the numerical results, and a decent correlation is observed between both results. In addition, the wave dissipation and flow field analysis near the vertical barrier are also shown using the numerical simulations. The experiments show that the wave reflection reduces with an increase in the dimensional water depth, and the pressure force on the vertical caisson breakwater increases with an increase in the barrier porosity. The performance of the horizontal slotted barrier is significant compared with the vertical slotted barrier in that it effectively distributes the incident wave into seaside wave energy and trapped wave energy. The study strongly believes that the pressure force is a trivariate function, i.e., wave height, barrier porosity, and free spacing available between the barrier and wall. The moderate barrier porosity and the higher free spacing help reduce the fluid force experienced by the vertical caisson breakwater. © The Author(s) 2025.