Author(s): Hany Ahmed; Anderias Schlenkof; Mohamed Ibrahim
Linked Author(s):
Keywords: Permeable breakwater; Vertical slotted wall; Semi-analytical model; Numerical model; Wave energy dissipation
Abstract: The present paper investigates the hydrodynamic performance characteristics of a pair of vertical slotted wall, which can be used as a permeable breakwater to protect the harbor and coastal areas. The proposed permeable breakwater model consists of a pair of identical vertical slotted walls with an impermeable upper and lower part, where the draft is a decimal multiple of the total depth. The middle part is permeable with a porosity of 50%. The second barrier is located at distances of 0. 25, 0. 5, 0. 75 and 1. 00 times of the wave length from the first one. For regular waves, using the Eigen function expansion method and the boundary condition at the breakwater, a semi-analytical model has been used to compute a wave transmission, reflection and energy dissipation coefficients. Laboratory experiments are conducted for the model of various values of structural parameters and wave period. Extensive studies using a numerical model (FLOW-3D, VOF) have been conducted to detect the influence of the chamber width. The laboratory experiments have been performed to assess both of the numerical and the semi-analytical model. A good agreement between experimental results and both of the numerical and semi-analytical results has been shown and the results indicate the applicability of the numerical model and semi-analytical to discover of the wave behavior through permeable breakwater. It is also of interest to compare the hydraulic performance of a single slotted wall with a pair of them to improve the benefits of using the second wall.
Year: 2015