Parametric Hull Design with Rational Bézier Curves

Antonio Mancuso,Antonio Saporito,Davide Tumino

doi:10.1007/978-3-030-70566-4_36

Antonio Mancuso, Antonio Saporito + Show 1 more

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https://doi.org/10.1007/978-3-030-70566-4_36

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Abstract

AbstractIn this paper, a tool able to support the sailing yacht designer during the early stage of the design process has been developed. Quadratic and cubic Rational Bézier curves have been selected to describe the main curves defining the hull of a sailing yacht. The adopted approach is based upon the definition of a set of parameters, say the length of water line, the beam of the waterline, canoe body draft and some dimensionless coefficients according to the traditional way of the yacht designer. Some geometrical constraints imposed on the curves (e.g. continuity, endpoint angles) have been conceived aimed to avoid unreasonable shapes. These curves can be imported in any commercial CAD software and used as a frame to fit with a surface. The algorithm and the related Graphical User Interface (GUI) have been written in Visual Basic for Excel. To test the usability and the precision of the tool, two sailboats with different characteristics have been replicated. The rebuilt version of the hulls is very close to the original ones both in terms of shape and dimensionless coefficients.

Highlights

In a wide range of industries, such as automobile, aircraft and shipbuilding [1], the first step of the process consists of finding an existing well designed geometry to be used as a benchmark for the new model
As far as the maritime field, it is interesting to notice that the design approach is mostly based on the traditional design techniques of trial-and-error
Other authors were more focused on the optimization phase as in [10] where a novel simultaneous engineering design approach has been proposed or in [2] where an interactive design approach for hull forms optimization is developed

Summary

Introduction

In a work of any engineer, the design is often the central and more important part of the entire process. To facilitate the design of hulls, naval engineers are investigating the possibility to define the so-called Hull Equation [4]. This equation should be able to describe, from a mathematical point of view the hull of a sailboat, a motorboat or a ship. Several works where authors present methods to generate a quick but detailed preliminary design or, on the other hand, approaches to optimize the geometry can be found in the literature. In [6] a design tool is developed using cubic polynomial expressions to define the control curves of a hull. A numerical tool able to help the yacht designer to properly define and modify the hull form of a sailboat has been written.

Design Approach

Case Study

Conclusion