• Journal of the Society of Naval Architects of Korea
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• v.34 no.4
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• pp.72-83
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• 1997

The purpose of present study is to find an appropriate hull shape of a container ship which can operate along the coast and through canals. A 200TEU class container ship is designed with dimensional modifications of an existing 140TEU container ship which is a domestic coastwise vessel. For the fore-body shape including bulbous bow. additional modification is done by changing the sectional area curve and frameline shape using the data of series resistance test. The model tests are performed in the towing tank to measure total resistance sinkage and trim of the model. And a finite-difference method based on MAC method is utilized to analyze the flow field around the ships in deep and restricted water. From the result of model test and numerical analysis, the resistance characteristics of the designed hull form are predicted.

• Journal of the Society of Naval Architects of Korea
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• v.31 no.2
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• pp.7-14
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• 1994

This paper describes the development of the interactive hullform transformation program. This program has many hull transformation functions such as main particular transformation, deadrise generation, section characteristic transformation, local transformation and CB, LCB variation, etc. MBASTRANS adopted the GUI(Graphical User Interface) using the OSF/Motif based on the X-Window system and used X-PLOT and GLBAX which are 2 and 3 dimensional graphic libraries, respectively. The interface module cans generate the information of the hullform for the SIKOB package and the hydrodynamic analysis.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.2
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• pp.496-506
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• 2014

In this paper the scenario based optimization of the bulbous bow of the KRISO Container Ship (KCS) is presented. The optimization of the parametrically modeled vessel is based on a statistically developed operational profile generated from noon-to-noon reports of a comparable 3600 TEU container vessel and specific development functions representing the growth of global economy during the vessels service time. In order to consider uncertainties, statistical fluctuations are added. An analysis of these data lead to a number of most probable upcoming operating conditions (OC) the vessel will stay in the future. According to their respective likeliness an objective function for the evaluation of the optimal design variant of the vessel is derived and implemented within the parametrical optimization workbench FRIENDSHIP Framework. In the following this evaluation is done with respect to vessel's calculated effective power based on the usage of potential flow code. The evaluation shows, that the usage of scenarios within the optimization process has a strong influence on the hull form.

• Journal of Ocean Engineering and Technology
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• v.28 no.6
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• pp.493-499
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• 2014

The resistance performances were studied for two 50-ft-class power yachts made of carbon fiber reinforced plastic (CFRP) with different hull form characteristics using model tests. The tests were carried out at a high-speed circulating water channel (CWC) for the 16–38 knot range. The total resistance, trim, and sinkage were measured, and the results were compared with wave patterns. The results showed that a chine position at the draft line had a strong effect on the planning performance and resistance performance in a certain velocity range.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.6
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• pp.1-7
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• 2006

This paper presents the study in the development of optimal working method for an outer-hull preprocessing robot using a quaternion. The out-hull preprocessing robot consists of feathering and cleaning parts. This robot should be controlled correctly for feathering work because it is to be worked on a curved plate that can result in the errors of orientation. In this paper, we propose a control algorithm between given two orientations of the out-hull preprocessing robot by using a quaternion with spherical linear interpolation. The proposed control algorithm is shown to be effective in terms of motor angles and torques when compared to a conventional Euler angle interpolation, by using both $MATLAB^{\circledR}$ and $VisualNastran4D^{\circledR}$.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.3
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• pp.1-7
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• 1999

This paper describes the modification of hull bottom for the air lubrication technique to the passenger boat in service at the Chung-Ju lake, which has a large beam-draft ratio. From numerical analysis of 2-D cavity problem by potential theory, the cavity shape, length and the pressure in cavity are estimated for the simplified geometry of hull bottom, and the non-dimensional parameters affecting air cavity phenomena are investigated. Extensive resistance tests for the model ship which has variation of step height and side strip have been performed to investigate the formation of air cavity and the drag reduction effectiveness. And also, the development of attached cavity to the bottom were observed from the flat bottom made by transparent acrylic plate. From this survey on the modification of bottom shape and the air lubrication technique, the total resistance of model ship could be reduced by about 25% at the design speed compared to the proto type hull form.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.6
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• pp.485-493
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• 2015

Planing hull form is widely used as a high speed vessel hull. There is a problem of the planing hull not solved yet. The problem is that the planing hull has very large vertical acceleration and large heave and pitch motions. As one method for overcoming this problem, there is "wave-piercing hull". Before the motion in waves is investigated, the resistance and running attitude must be investigated. In this paper, the running attitude and resistance of two wave-piercing hulls are investigated by model tests. Model test results show that the wave-piercing hulls have large trim angle and sinkage at the high speed, so additional model tests are conducted by using the hull appended by stern interceptor that is very thin plate to increase the hydrodynamic pressure at the attached location. The results are compared with other planing hulls and the resistance components and the hydrodynamic force are discussed. From the model test results, it can be known that the stern interceptor is the effective appendage for the reduction of the resistance and trim angle of wave-piercing hull.

• Journal of the Society of Naval Architects of Korea
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• v.37 no.2
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• pp.109-117
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• 2000

In order to develope ship hull forms. many various models are represented numerically in terms of B-spline surfaces and tested experimentally in the towing tank. It is very difficult to make various ship hulls with free forms in handiwork. As the first step of development of a free form cutting machine which becomes a good substitute for high-priced model cutting machines, free forms representation for model cutting are developed. In this paper, NURBUS surfaces are represented on the assumption that data points may be control points contrary to existing methods.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.05a
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• pp.237-242
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• 2002

최근 우리나라 연안어업은 한일, 한중어업협정, WTO 가입 등으로 주변 환경이 급격하게 변화되는 한편, 연근해 어자원의 감소와 근해어업과의 경쟁조업 등으로 인해 경영수지가 극도로 악화되고 있다. 이로 인해 연안어민들의 최소 생계기반 마저 위협받고 있는 실정이다. 이에 본 연구는 연안어업의 수익향상과 자원관리 측면에서 경제성 연안 어선의 선형개발 방안을 검토하였다. 이를 위해 새로운 어선어업 환경에서 요구하는 자원관리, 채산성보장 등의 경제 사회적 요건을 기술적 요소로 변환하여 다목적어선의 개념을 설정하고 관련 기초자료를 마련하였다. 특히, 연안어업을 동해, 서해, 남해, 서남해 등으로 나누어 허가업종의 실태와 어민 요구사항이 서로 다른 점을 감안하여 다목적화 가능 업종을 선정하고, 선형개발 방안을 도출, 정리하였다.

• Journal of the Society of Naval Architects of Korea
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• v.45 no.6
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• pp.590-600
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• 2008

This paper concerns the development of a designer friendly hull form parameterization and its coupling with advanced global optimization algorithms. As optimization algorithms, we choose the Partial Swarm Optimization(PSO) recently introduced to solve global optimization problems. Most general-purpose optimization softwares used in industrial applications use gradient-based algorithms, mainly due to their convergence properties and computational efficiency when a relatively few number of variables are considered. However, local optimizers have difficulties with local minima and non-connected feasible regions. Because of the increase of computer power and of the development of efficient Global Optimization (GO) methods, in recent years nongradient-based algorithms have attracted much attention. Furthermore, GO methods provide several advantages over local approaches. In the paper, the derivative-based SQP and the GO approach PSO are compared with their relative performances in solving some typical ship design optimization problem focusing on their effectiveness and efficiency.