Flexible Floating Breakwater

A.N. Williams, P. T. Geiger, William G. McDougal

Journal of Waterway Port Coastal and Ocean Engineering · 1991 · 54 citations · 7 references

Concepts

TL;DR

The study models wave interaction with a floating breakwater as a linearized two‑dimensional potential flow acting on a one‑dimensional beam of uniform flexural rigidity and mass per unit length under constant axial force. A numerical model based on a boundary‑integral equation for a compliant, beam‑like floating breakwater—anchored to the seabed, tensioned by a buoyancy chamber, stiffened by mooring lines, and described with a Green’s function—was developed and validated against small‑scale physical tests. Numerical simulations show how wave and structural parameters influence breakwater efficiency, and experimental validation confirms the model’s predictions with reasonable agreement, though with notable scatter.

Abstract

A numerical model is developed to analyze a flexible, floating breakwater consisting of a compliant, beam‐like structure anchored to the sea bed and kept under tension by a small buoyancy chamber at the tip. Additional stiffness is provided by mooring lines. The fluid motion is idealized as linearized, two‐dimensional potential flow and the breakwater is idealized as a one‐dimensional beam of uniform flexural rigidity and mass per unit length subjected to a constant axial force. The boundary integral equation method is applied to the fluid domain. Modifications are made to the basic formulation to account for the zero thickness of the idealized structure, and the dynamic behavior of the breakwater is described through an appropriate Green's function. Numerical results are presented illustrating the effects of the various wave and structural parameters on the efficiency of the breakwater. Small‐scale physical model tests were also carried out to validate this theory. In general, the agreement between experimental and numerical results was reasonable, but with considerable scatter.

References

7