LAUSR

This study investigated the hydrodynamic performance of a system consisting of a rigid, bottom-mounted, surface-piercing cylinder coaxially surrounded by a partially immersed coaxial compound cylindrical breakwater to optimize its configuration to improve the response to capillary–gravity waves. The compound breakwater consists of two impermeable, thick-walled cylinders of the same radius placed vertically in the water column and connected by an intermediate porous hollow cylinder of the same radius. The analysis is done using linear wave theory. Velocity potentials in each fluid region are derived using the eigenfunction expansion method, and unknown coefficients are obtained by applying appropriate matching conditions at the interfaces. Hydrodynamic quantities such as wave forces, free surface elevations, added mass, and damping coefficients for surge and pitch motions are evaluated. It is observed that the draft of the porous hollow cylinder and thick cylinder of the compound breakwater, along with the porous parameter, has a significant influence on all evaluated hydrodynamic parameters.