Apart from widely used of porous structure in coastal area, a comprehensive study of spatial wave-structure interaction and turbulence flows evolution is still lacking. Wave-structure interaction and turbulent flows were studied experimentally in an idealized stepped-type porous breakwater with slope of 1:15. Incident waves of nonbreaking and spilling-type breaking waves were used in the experiments. The velocity fields were measured using particle image velocimetry (PIV) technique. The data were analyzed using an ensemble average method by repeating the same experiment multiple times. Evolution of the ensemble-averaged flows, including vorticity, turbulence dissipation rate, turbulent kinetic energy, and Reynolds stress in the structure were investigated. The velocity fields and turbulent flows within the structure were also reported. The energy dissipation rate, wave pressure, and wave profile measurements were measured to study the interaction effect of the structure. Higher velocity was generated in the transition region between permeable and impermeable region. Within the structure, turbulence and higher vorticity were generated. Having higher turbulence within the structure, the dissipated wave energy was also significant, which is advantageous to protect the coastal area

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