Session: 

Submission Number: 180432

Hydrodynamic Analysis of a Floating Breakwater With Perforated Skirt Plates 

Floating breakwaters offer a flexible, relocatable, and environmentally friendly solution for creating sheltered waters in areas where traditional fixed breakwaters are impractical or too costly, such as deep or soft seabeds. This study investigates the hydrodynamic performance of a box-type floating breakwater fitted with front and rear perforated vertical skirt plates designed to enhance wave attenuation and reduce dynamic responses.

Using linear potential flow theory and the Boundary Element Method, various fluid–structure interaction models through perforated plates are examined, with emphasis on linear and nonlinear pressure drop formulations. Model validation against experimental data for fixed perforated cylinders confirms that nonlinear (quadratic) pressure drop models provide more physically consistent predictions of flow resistance. The validated quadratic model and the conventional linear model are then employed to analyse wave-induced forces, structural motions, and transmitted wave fields for the floating breakwater with perforated skirts.

Results reveal that incorporating porosity in the skirt plates significantly reduces excitation forces and peak heave motions compared with impermeable designs. Moreover, the perforated configuration achieves superior wave attenuation and energy dissipation relative to traditional box-type floating breakwaters. These outcomes highlight the potential of perforated skirt designs in improving the stability, effectiveness, and adaptability of floating breakwaters for coastal and offshore applications. The study also shows that linear pressure drop models capture consistent behavioural trends with the more accurate quadratic model, with deviations of approximately ±15% in predicted hydrodynamic responses, suggesting their continued utility for preliminary design assessments.

Presenting Author: Huu Phu Nguyen University of Queensland

Presenting Author Biography: Dr. Nguyen’s research interests are in the areas of ocean energy converters and large floating structures. He has developed numerical methods for analysing the interaction between ocean waves and several marine structures (large floating platforms, wave energy converters and floating breakwaters). He is working on: (i) attaching perforated/porous elements (such as perforated plates) to floating structures for increased safety and cost-effectiveness; and (ii) developing floating platforms for farming seaweeds.

Authors:

Huu Phu Nguyen University of Queensland
C. M. Wang University of Queensland