Hydrodynamic Design of a Fast Semi-SWATH Passenger Ship for Littoral Applications: an Automatic Parametric Optimization Approach

Giuliano Vernengo, Stefano Brizzolara, Dario Bruzzone (Innovative Ship Design Lab, University of Genoa)

CHALLENGE – A semi-SWATH (Small Waterplane Area Twin Hull) designed for littoral passenger transport service is optimized by an automatic procedure with respect to seakeeping and resistance at different speeds. A new vessel design based on this unconventional hull form optimized for both seakeeping and resistance is a major step forward towards a sustainable and resilient littoral transportation in the Ligurian gulf (north Tyrrhenian Sea).

SOLUTION – 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. NSGA-II, provided by modeFRONTIER software, drove the optimization process.







BENEFITS – Optimum hull forms obtained by the numerical procedure allow significant improvements of the hydrodynamic performance: 13% resistance reduction at high speed, greater than 25% resistance reduction at lower speed and more than 70% lower vertical acceleration in head waves with respect to the initial design. This level of reduction is not possible with a traditional trial and error procedure and without multi-objective software like modeFRONTIER.