Floating breakwater concept for large LNG terminals. Part 2: optimization

Abstract

In sequence of Part 1 of this two-part paper, this article describes the development and application of an optimization model developed for the design of a floating breakwater that has the main function of protecting large LNG vessels from sea waves. The model consists basically of a parametric model coupled to an optimization algorithm that evaluates a variety of breakwater geometries and searches for the one presenting the lowest construction cost, subjected to different constraints such as wave attenuation capability, stability margin, maximum structural loads, and uptime level. This methodology is applied to Uruguay’s coastal waters, which place is chosen because it presents harsh sea states in the Atlantic South region and would thus represent a big challenge for the feasibility of a floating breakwater. Results are discussed in terms of the geometry that presented the lowest cost considering an uptime level greater than 90%. For this geometry, a mooring system arrangement is also proposed in order to keep breakwater positioning passively while satisfying the maximum offset requirements.