Dissipation of Incident Wave Energy by Two Submerged Horizontal Porous Plates Over a Pair of Trenches

Abstract

Abstract: In this paper, the interaction of oblique water waves by two non-uniform submerged horizontal porous plates in the presence of a pair of trenches is analyzed towards the study of effective breakwater. The problem is modeled based on Darcy’s law for flow past a porous structure. The series solutions through matching conditions establish an over-determined system of equations, which is solved using the least-square method, giving rise to results for essential quantities such as dissipation coefficient, transmission and reflection coefficients, elevation and force whose graphs are oscillatory as a function of gap length. The study reveals that the submergence depth D=0.2 is the best value for many values of gap length, producing more dissipation and less force on the barriers. It is also found that after the critical angle, the force for all submergence depths is almost same. The porosity plays an important role in avoiding zero reflection and full transmission which will oscillate periodically with maxima and minima occurring. Hence, two submerged horizontal porous plates over uneven bottom topography will play a vital role in constructing an effective submerged breakwater reducing high wave impact.