Hydrodynamic design of a fast semi-SWATH passenger ship for littoral applications: An automatic parametric optimization approach

A semi-SWATH (Small Waterplane Area Twin Hull) designed for littoral passenger transport service is optimized by a full automatic procedure with respect to seakeeping and resistance at different speeds. The computer assisted procedure is based on: A fully parametric model of the unconventional hull form, which guarantees ample shape changes while ensuring the fairness of the surfaces; on 3D linear Rankine sources panel method for the steady wave resistance and seakeeping problem; and on multi-objective global convergence genetic algorithms. Both global (length and demi-hull beam) and local shape variations are allowed in order to explore highly unconventional hull shapes. Interesting results are obtained from the optimization considering resistance at a single speed or two very different speeds and including or not the seakeeping merit functions. Considerable reductions of drag and vertical acceleration can be obtained from the optimization procedure in the order of 15% on drag at high speeds and 30% on vertical acceleration in most exposed passenger area. Copyright © 2014 by the International Society of Offshore and Polar Engineers (ISOPE).