Hydrodynamic analysis of a multi-arc composite breakwater under wave action

This study presents a theoretical model for wave scattering from a multi-arc breakwater—a structure of concentric, thin-walled, and bottom-mounted arcs. The arcs can be either impermeable or porous. Using linear potential flow theory, the model employs the eigenfunction matching method and the Galerkin method to solve the hydrodynamic problem. Following convergence analysis and validation against previous data, the solution provides the excitation forces on the arcs and the surrounding wave elevation. The theoretical results show that while effective at attenuating waves, the breakwater can induce complex circumferential and radial resonances typically associated with low and high frequencies, respectively, which is a critical consideration for engineering applications.