Mitigation of wave force and dissipation of energy by multiple arbitrary porous barriers

Abstract

A model of oblique wave diffraction by multiple arbitrary porous barriers in infinitely deep water is proposed to study the role of the porous breakwater in mitigating wave effects and dissipating wave energy. The Havelock's expansion of water wave potential along with suitable matching conditions and the single term Galerkin approximation method are used to handle the mathematical boundary value problem. The role of the arbitrary porous barrier is studied by analyzing the reflection coefficient, dissipated energy, and wave forces on the barriers. Significant changes are found in wave reflection and forces due to the consideration of porous barriers as compared to rigid barriers in the fluid region. As the separation length between the vertical barriers increases, the reflection coefficient becomes oscillatory as a function of the wavenumber, which is due to multiple reflections by the barriers. It is seen that the wave load reduces significantly with an increase in the number of barriers. It is also found that more energy is dissipated if the permeability of the barriers is increased. The correctness of the present method is confirmed by comparing the results available in the literature.

Keywords:

• Water wave scattering
• Galerkin approximation
• porous barrier
• reflection and transmission coefficients
• energy dissipation
• wave force

Acknowledgments

The authors would like to gratefully acknowledge the Editor and Reviewers for their valuable comments and suggestions to improve the quality of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.