Wave scattering by a partial flexible porous barrier in the presence of a step-type bottom topography

Abstract

A semi-analytic model is presented for oblique wave scattering by a bottom-standing or surface-piercing flexible porous barrier in water of finite depth with a step-type bottom topography. The physical problem is solved using the methods of least-squares and multi-mode approximation associated with the modified mild-slope equation. Effects on the wave scattering due to bed profile, structural rigidity, compressive force, angle of incidence, barrier length, porosity, and height of the step are examined. The study reveals that under some special conditions, nearly zero/full reflection may occur in the case of wave scattering by a partial flexible porous barrier in the presence of an undulated bottom topography. Further, the study predicts that the Bragg resonance may not occur in the case of wave scattering by a topography of sinusoidal profile. The present study provides insights to help understand how waves are transformed in a marine environment with/without flexible porous barriers in the presence of a bottom topography. The concept and methodology can be generalized to analyze problems of similar nature arising in ocean engineering.