Y. Ryu - Hydro Science & Engineering Research Institute, Korea Institute of Civil Engineering and Building Technology, Goyang ۴۱۱-۷۱۲, Republic of Korea
D. Hur - Dept. of Ocean Civil Engineering (Institute of Marine Industry), Gyeongsang National University, Tongyeong ۶۵۰-۱۶۰, Republic of Korea
S. Park - Dept. of Naval Architecture and Ocean Engineering, Pusan National University, Busan ۶۰۹-۷۳۵, Republic of Korea
H. Chun - Dept. of Naval Architecture and Ocean Engineering, Pusan National University, Busan ۶۰۹-۷۳۵, Republic of Korea
K. Jung - Dept. of Naval Architecture and Ocean Engineering, Pusan National University, Busan ۶۰۹-۷۳۵, Republic of Korea

The purpose of this study was to investigate the effect of the porosity of a submerged breakwater on wave fields, including snapshots of the wave, velocity profiles of the water over the structure, and the kinetic energy of the wave. Two-dimensional experiments were conducted for submerged trapezoidal breakwaters with impermeable and permeable layers in a two-dimensional wave tank. The flow fields obtained by the particle image velocimetry (PIV) technique are presented to understand the flow characteristics due to the waves’ interactions with the submerged impermeable and permeable breakwaters, and these characteristics showed that the vertical velocity dominant flow occurred under the crest of the wave. In addition, the kinetic energies were compared for different porosities and wave conditions. The comparisons of the wave flow fields and kinetic energy distributions showed that the different pattern of the dissipated kinetic energy was dependent on the porosity. The dissipation of kinetic energy also was observed to increase as the wave period increased. The comparisons indicated that greater amounts of energy were dissipated for longer wave periods.

SubSubmerged breakwater, Energy dissipation, velocity profile, Permeability.merged breakwater, Kinetic energy, Wave energy dissipation, Wave kinetic energy, Permeability