Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

A Ship Hull Optimization for Low Resistance and Uniform Wake Based on the Simulation ofHydrodynamics Performance
Yinhao Li [2] [3], Xiechong Gu* [1] [2] [3], Ning Ma [1] [2] [3], Yi Zhang [2] [3]
1. State Key Laboratory of Ocean Engineering, Shanghai, China;
2. School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai, China;
3. Institute of Marine Equipment, Shanghai Jiao Tong University, Shanghai, China;

optimization of the bow and stern to minimize ship resistance andimprove the wake behind the stern to make the flow incident to thepropeller more uniform and gaining a more higher propulsion efficiency.
With the development of CFD simulation, hydrodynamic ship
performances, such as resistance, propulsion and etc., are more likely
predicted by numerical simulation, and tests performed in towing tankare becoming a final confirmation of a design. In this way, today’s ship
design is more and more relied on numerical simulation, and such adesign of ship hull is known as simulation-based design, i.e. SBD, which
consists of three components, namely, geometry expression of the ship
hull, performance prediction by simulation, and searching strategy forthe hull form with optimal performance. Simulation based design inseeking for optimal hull form with reduced resistance is becoming acommon practice in ship design. Sharma, Kim, Storch, Hopman andErikstad (2011) reviewed the application of computer technology inmethodology, modeling and the integration of ship design system andanalysis involved. Tahara, Tohyama and Katsui (2006) conducted adevelopment of SBD by integrating computer-aided design (CAD) for
hull geometry, CFD for performance simulation, and an optimizer
module into a system. At the same time, Harries (2006) practiced
resistance reduction and capacity increase for a medium-size container
carrier by means of adjusting the shape of sectional area curve in termsof morphing approach, and received a good result. Hyunyul Kim and ChiYang (2009) also focused on the sectional area curve of hull, and the hull
form is interpolated by means of radial basis functions, i.e. RBF, andperformed optimization to minimize resistance for KCS in terms of theirin-house so-called practical design-oriented CFD tool, namely SSF.
Recently, Nazemian and Ghadimi (2021) also applied RBF-morph
technique in resistance minimization for a trimaran hull at two design
speeds, and received a reduction of resistance by 6.77% at low speed,
and by 1.55% at high speed. Kim, Choi and Chun (2016) devised aparametric modification function to perform deformation of the ship hullexpressed as B-spline surface, and received reduction of wave making
resistance by 7.5% for KCS, reduction of viscous pressure resistancecoefficient by 6.2% for KVLCC2. Liu, Wang and Wan (2018) applied
the free-form deformation method, FFD, to perform deformation of thehull form of KCS in minimization of resistance at whole speed range.
Zhao, Wang, Jia, Xie (2021) chose an ocean-going trawler as parent shipand used FFD to deform the bulbous bow Lackenby method to deformthe hull. As a result, the resistance under the trawling and design

ABSTRACT
A ship hull form optimization is conducted for KCS focusing on theshape of bow and stern. Shape of the hull form is expressed in a radialbasis function to facilitate its deformation during the course ofoptimization. Optimization of stern focuses mainly on improvement of
the quality of the wake to increase propulsion efficiency potentially,
while the bow optimization aims at the reduction of total resistance. In
the optimization, a Kriging model is constructed to replace actualhydrodynamic performances of the ship by a model based on Latin
hypercube sampling. Multi-island genetic algorithm and non-dominatedsorting genetic algorithm-Ⅱ are employed in the optimization to prevent
pre-mature termination at local optimal solution rather than global
optimal solution. As a result, the total resistance of KCS at service speed
is reduced by 1.36% and the wake object function (WOF), proposed by
MARIN, is reduced by 10.2%. The method coordinated in this study
could be applied in ship hull optimization problem for otherhydrodynamic performances.

KEY WORDS: ship hull form optimization; radial basis function;
Kriging model; ship resistance; wake object function.

INTRODUCTIONNowadays shipping industry plays a more important role than everbefore in international transportation. With the increase of attention toenvironment protection, greenhouse gas emission has to be reduced aswell in ship transportation. The international maritime organization,IMO, at her 75th meeting of Marine Environment Protection Committee(MEPC) has presented that the energy efficiency design index (EEDI)"phase 3" requirements of container ships will enter into force at dateof 1 April 2022. In order to meet the EEDI requirement, further reductionof ship resistance is still a topic for all of the ship designers, since ship
resistance is a great concern of fuel consumption and closely related to
the greenhouse gas emission. Design of optimal hull form is the originof resistance reduction. Based on this consideration, construction of aship hull optimization system is an urgent task. Generally, ships usually
look like a slender cylinder, variation of the cross-section mainly lies inthe bow and stern parts. In this study, we will integrate a system for3478