Experimental study of hydraulic response of smooth submerged breakwaters to irregular waves

This paper presents the results of a laboratory experiment on transmission, reflection, and dissipation of irregular waves over smooth impermeable submerged breakwaters. Experiments included 75 JONSWAP-based irregular waves with five different wave characteristics generated at three water depths in a 2D wave flume. The investigated breakwater sections were three rectangular breakwaters with different widths, a toothed rectangular breakwater, and a trapezoidal breakwater with a slope of 1:2. A new comprehensive dimensionless parameter ( beta) was proposed representing both wave hydrodynamic and breakwater geometry characteristics. This parameter could be employed as a suitable descriptive option to make an accurate estimate of the hydraulic performances of submerged breakwaters. The beta parameter is composed of four conventional simple dimensionless variables. However, the results revealed that the relative submergence depth significantly affects the hydraulic responses of submerged breakwaters. The transmission, reflection and dissipation of waves show a logarithmic growth, a logarithmic reduction, and a quadratic decreasing trend against the increasing of beta parameter, respectively. The verifications of results revealed the high efficiency of beta parameter for data reported by Carevic et al. (2013) with R 2 = 0.88 and high agreement with predictions made by Van der Meer et al. (2005) formulation with R 2 = 0.93. (c) 2021 Institute of Oceanology of the Polish Academy of Sciences. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ).