The hydrodynamic characteristics of a single suspended row of half pipes under regular waves

In this paper, the hydrodynamic performance of a new type breakwater is studied using physical models. The breakwater consists of one row of half pipes suspended on supporting piles. The transmission, the reflection, and the wave energy dissipation coefficients are presented for different wave and structure parameters. The results indicate that the performance of the proposed breakwater becomes efficient when: (1) the half pipes are horizontal; (2) the diameter of the half pipes is increased; (3) the breakwater inclination angle is 45°; (4) the breakwater draft is greater than the half of the water depth; and (5) the wavelength is more than two times the water depth. In addition, the proposed breakwater type gives high performance when compared with the other similar breakwater systems, e.g. suspended vertical or horizontal pipes and slots, by about 5%–40%.

► A physical model is presented for half pipe breakwaters.
► The proposed half pipes breakwater is better than the vertical smooth wall type.
► System gives transmission coefficients 5%–15% less than smooth vertical wall.
► It gives reflection coefficient from 5% to 10% less than the smooth vertical wall.
► It dissipates wave energy 5%–22% more than the smooth vertical wall.