Page 84 - Practical Design Ships and Floating Structures

Practical Design of Ships and Other Floating Structures 59
You-Sheng Wu, Wei-Cheng Cui and Guo-Jun Zhou (as)
0 200 I Elsevier Science Ltd. All rights reserved

THE FINE OPTIMIZATION OF SHIP HULL LINES
IN RESISTANCE PERFORMANCE BY USING CFD APPROACH

L. Xu and Y. Y. Wang

Department of Naval Architecture Dalian University of Technology
Dalian 116024. China

ABSTRACT

In order to complete the fine optimization of ship hull lines, a classified optimization procedure is
developed in this paper. Altogether 5 levels are included in this procedure. Level 0 is optimization of
hull dimensions based on the method of experience or statistical formulae. Levels I, 2 and 3 are
optimizations of naked hull lines, local hull lines and appendage lines respectively. The method of
Navier-Stokes equations is used with thick-layer approximation and integral numerical approach for
Level I, with thick-layer approximation and differential numerical approach for Level 2, and with
partly-parabolic approximation and differential numerical approach for Level 3. Level 4 is optimization
of finalized hull lines by using model test with flow field measurements. The practical design of ship
hull has shown that CFD code is applicable for optimization of ship hull lines in the view of hull
resistance performance.

KEYWORDS

Hull resistance, Regressive analysis, Reynolds Average Navier-Stokes equations, Integral numerical
approach. Differential numerical approach, Optimization procedure, Ship design.

1 INTRODUCTION
The optimization of ship form is a traditional approach in ship design and one of contents is the
optimization of ship hull lines. It can be seen that the optimization technique is continuously improved
along with the development of engineering science especially with the development of computer and
numerical techniques.

So called optimization of ship hull lines may be regarded as lines fairing only, but this is not
comprehensive both in theoretical category and in engineering practice. In fact optimization or fairing
of ship hull lines can not be seen as pure mathematical or geometrical problem because it should
satisfy so many engineering requirements, such as loading, general arrangement, hydrodynamic
performance, and structure consideration. From this viewpoint it may be more suitable that the
optimization approach is called the weighing design for ship hull lines.