Hydrodynamic analysis on diffractions of linear water waves by a ?-shaped surface-piecing breakwater over uneven bottoms

Abstract

The hydrodynamic behavior of water waves interacting with a surface-piecing pi-shaped breakwater over uneven seabed configurations is analyzed using the eigenfunction matching method (EMM). The continuous seabed is modeled by shelves separated by steps. By employing eigenfunctions with unknown coefficients, the conservations of mass and momentum for each step are formulated into a system of linear equations. The hydrodynamic forces and moment on a variable floating breakwater with and without barriers over variable bottom are formulated. In the absence of thin vertical barriers, the system simplifies to the case involving a floating breakwater over variable bottoms. To assess the accuracy of the proposed model, the computed results are compared with the existing data from the literature, demonstrating excellent agreement. The model is further applied to investigate wave diffraction characteristics. Reflection and transmission coefficients, as well as wave forces, are analyzed in relation to various geometric parameters. Numerical results indicated that the pi-shaped floating breakwater significantly alters wave diffraction patterns and energy distribution. Additionally, the structure is shown to reduce excitation wave forces when subjected to incoming waves.