Giuliano Vernengo

Risk-Adaptive Set-Based Design and Applications to Shaping a Hydrofoil

The paper presents a framework for set-based design under uncertainty and demonstrates its viability through designing a super-cavitating hydrofoil of an ultra-high spee d vessel. The framework achieves designs that safely meet requirements as quantified precisely by superquantile measures of risk (s-risk) and reduces the complexity of design u nder uncertainty. S-risk ensures comprehensive and decisio ntheoretically sound assessment of risk and permits a decoupling of parametric uncertainty and surrogate (model) uncertainty. The framework is compatible with any surrogate building technique, but we illustrate it by developing for t he first time risk-adaptive surrogates that are especially tai lored to s-risk. The numerical results demonstrate the framework in a complex design case requiring multi-fidelity simulatio n.

A combined approach based on Subdivision Surface and Free Form Deformation for smart ship hull form design and variation

ABSTRACT Techniques for shape representation and further modification of a hull surface definitely play a key role in both the design of new buildings and in the optimisation of the existing ones. The simplification of the methods is the goal to reach in order to create useful tools for real applications. A new approach for hull shape modification is proposed. It is based on a combination of the Subdivision Surface technique for hull surface modelling and Free Form Deformation for shape variation. The formal relation between the two methods is established by the Free Form Deformation control volume and the Subdivision Surface control polygon, introducing significant simplification to the definition of the transformation. The new approach is described in detail highlighting its benefits. Its effectiveness is finally proved by an example of application on a real hull shape, where a combination of a local and global modification has been analysed.

Logistics-based fleet design for complex transportation scenarios

ABSTRACT A new integrated method for the preliminary design of a fleet of ships for a new trade is presented. Data from two apparently separate types of analysis, based on logistics and naval architecture, are merged within an integrated logistics-fleet design framework. The procedure carries out a preliminary screening of the design space based on logistics criteria. Then, possible fleet configurations and ship designs are investigated, providing information to shipyards and ship owners for an effective selection of optimal solutions. Interactions between logistics evaluations and classic ship design assessments are highlighted. Results from a realistic test case concerning compressed natural gas transportation are presented and discussed.