Page 92 - Practical Design Ships and Floating Structures

Practical Design of Ships and Other Floating Structures 61
You-Sheng Wu, Wei-Cheng Cui and Guo-Jun Zhou (Eds)
6 2001 Elsevier Science Ltd. All rights reserved

PARAMETRIC HULL FORM DESIGN -
A STEP TOWARDS ONE WEEK SHIP DESIGN

C. Abt, S.D. Bade, L. Birk, S. Harries
Institute of Land and Sea Transportation
Technical University of Berlin Germany

ABSTRACT
This paper presents a parametric modelling approach to the design of ship hull forms which allows to
create and vary ship hulls quickly and efficiently. A design-oriented parametric definition language is
introduced which features high-level descriptors of hull characteristics well-known in naval
architecture. A modelling system is presented that produces a complete mathematical description of
the hull via geometric optimisation, enabling effective shape variations by keeping selected parameters
constant while adjusting others automatically. All curves and surfaces yield excellent fairness.
Examples illustrate parametric shape design and variation. Thus, the parametric modelling approach
provides the ideal basis to hydrodynamic optimisation and one week ship design.

KEYWORDS

Hull form design, Parametric modelling approach, Geometric optimisation, One week design

1 INTRODUCTION

In order to be competitive on the market, preliminary ship design has to be performed in continually
decreasing time spans. Accurate estimation of weights, building cost and performance are essential for
the success of a bid. Decision-taking at the early design stage fixes the major expenses while
uncertainties about the upcoming costs have to be reduced as much as possible. A considerable number
of design alternatives and their thorough evaluation increases the competitiveness of a shipyard.
Selecting a design from a larger stock or being able to create designs of high quality on demand offers
a huge advantage. The ultimate goal of advanced modelling systems for future developments is to
provide a complete generic model for the entire ship which includes production as well as lifecycle
costs. However, software tools applied in the preliminary design phase today generally feature a
different view of ships than geometric modelling systems. Moreover, using state-of-the-art computer
simulations, for instance CFD and FE methods, require a complete geometric representation of the ship
- mostly in discretized form.
This paper therefore aims at introducing a new approach to hull form design based on a parametric,
design-language-oriented definition. Different descriptors used by the various partners involved in the