Abstract
The hydrodynamic performance of composite wavy submerged porous plate attached to a wall is investigated using numerical method MDBEM (Multi-domain boundary element method) in the linearized water wave theory in which wave past the porous barriers are modelled using Darcy law. Effect of the presence of wall on the hydrodynamic parameters like reflection coefficient, dimensionless wave height, wave force and moment acting on the composite wavy porous structure and horizontal force on the vertical rigid wall is analyzed for various physical parameters like the number of ripple wavelength, structural porosity, submergence depth and relative amplitude of composite wavy porous plate. The study demonstrates that the efficiency of hydrodynamic characteristics of the composite wavy porous plate attached to the wall is better compared to a horizontal porous plate attached to the wall of the same applicability conditions (around 27% reduction in wave reflection). Moreover, optimum performance of this kind of breakwater system is increased by considering the lower submergence, higher relative ripple amplitude, appropriate relative amplitude and suitable moderate porosity of the structure in the range of wave number 1 < k0h < 5. Dimensionless wave height, horizontal load on the impermeable wall are reduced to zero, whilst substantial minimization of vertical load on the structure with suitable consideration of the other influencing parameters of porosity Gp = 0.3, relative amplitude Ds/h = 0.1, relative ripple wavelength m > 3 and submergence depth h1/h = 0.3. The present structural arrangement will be useful for attenuating wave effects on the sea wall.
On hydrodynamic characteristics of gap resonance between two fixed bodies in close proximity
