Wave energy dissipation by a floating horizontal porous plate in oblique incident waves

Abstract

The interaction of oblique incident waves with a floating porous plate has been investigated using the matched eigenfunction expansion method (MEEM). The porous boundary condition based on Darcy’s law is applied at a floating porous plate (Zhao et al. (2009)). Depending on the presence of a vertical rear wall, the wave energy dissipation by a floating porous plate is evaluated with two analytical models: wave barrier and wave absorber. The nonlinear dispersion equation, derived from the porous boundary condition, is solved numerically by using Muller’s method to obtain the complex-number eigenvalues in the porous-plate covering region. Notably, it is confirmed that the real part of the first-mode eigenvalue is closely related to the energy dissipation due to the generation of vortices when waves propagate past a floating porous plate, and the porosity parameter b=5.0 (plate porosity P=0.1) is found to be the optimal value for the maximum energy dissipation. The analytical solutions are validated by means of the model test with a floating porous wave barrier.