• Journal of Ocean Engineering and Technology
• /
• v.32 no.4
• /
• pp.215-221
• /
• 2018

In this study, the optimal design of a mooring system was carried out. Unlike almost all design methods, which are based on the deterministic method, this study focused on the probabilistic method. The probabilistic method, especially the design of experiment (DOE), could be a good way to cover some of the drawbacks of the deterministic approach. There various parameters for a mooring system, as widely known, including the weight, length, and stiffness of line. Scenarios for the mooring system parameters were produced using the Latin Hypercube Sampling method of the probabilistic approach. Next, a vessel-mooring system coupled analysis was performed in Orcaflex. A total of 50 scenarios were used in this study to optimize the initial design by means of a genetic algorithm. Finally, after determining the optimal process, a reliability analysis was performed to understand the system validity.

• Journal of the Society of Naval Architects of Korea
• /
• v.35 no.3
• /
• pp.38-45
• /
• 1998

In this parer, the effects of a skeg, rudder and stern hull form on the manoeuvrability of a container carrier with small length to draft ratio have been investigated through a series of model test. Rudder open water tests and PMM tests were carried out with varying rudder area, afterbody appendages and stern hull form to investigate their effects on the manoeuvrability. The MMG model developed in Japan was used for the manoeuvring simulation with experimentally obtained hydrodynamic coefficients. The result showed that the effects by the variation of stern profile and the skeg below stern bulb are much larger than those by any other types of appendages in improving directional stability of the vessel.

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

• Bulletin of the Society of Naval Architects of Korea
• /
• v.26 no.1
• /
• pp.1-10
• /
• 1989

When a ship is travelling in following seas, the encounter frequency is reduced to be very low. n that case surf-riding, broaching-to and capsizing phenomena are most likely to occur. In the present paper, the emphasis is laid upon the transverse stability of ships in following seas, which is related to capsizing phenomenon. The authors intend to clarify the mechanism of the stability variation in following seas. In order to predict that variation, the theoretical calculation method and computer programming are developed. The theoretical calculation is based on Froude-Krylov Hypothesis and static equilibrium condition in waves. Through the application of present calculation method to cargo vessel and fishing boat, it is verified that the transverse stability in following seas with crest amidships can be reduced to a half extent in comparison with calm water stability. On the other hand, the present calculation results are compared with existing experimental data.

• Journal of the Society of Naval Architects of Korea
• /
• v.49 no.6
• /
• pp.541-549
• /
• 2012

The study adopted a freezing prevention method of the upper deck which used heating coil, and carried out numerical analysis by using ANSYS 13.0 CFD for design guide of the vessel operating in cold region. It is based on the experimental results of the anti-icing performance tests which were carried at cold room chamber in MOERI. Numerical analysis for the design guide was performed by considering S.S.T. (Shear Stress Transport) turbulent model for flow separation effects and the turbulence which occurred in interfaces of the numerical model in order to express appropriate heat transmission phenomenon. The numerical result shows average temperature of the upper deck surface appeared similarly compared with the indoor chamber test. The design guide for optimum freezing prevention presented through heat transmission capability and interval of the heat coil in various outdoor temperature($10^{\circ}C{\sim}-30^{\circ}C$) and wind speed(1m/s~7m/s).

• Journal of the Society of Naval Architects of Korea
• /
• v.44 no.3 s.153
• /
• pp.340-347
• /
• 2007

Main purpose of the study is to develop a transit model for icebreaking cargo vessels in the Northern Sea Route and to select optimum sea routes with the shortest navigation time and the lowest operation cost. This numerical model executed with basic information such as ship capabilities, transit directions and months of transit, can calculate total transit distance and elapsed time, mean speed, operation cost for each vessel. In the transit model. environment information such as the site-specific ice conditions, wave and wind states are utilized for four different months (April, June, August, and October) along the Northern Sea Route. The model also defines a necessary period of an icebreaker escort. Then the optimum sea routes are selected and visually displayed on the digital map using a commercial software ArcGIS. Usefulness of the selected sea routes is discussed.

• Journal of the Society of Naval Architects of Korea
• /
• v.44 no.3 s.153
• /
• pp.285-295
• /
• 2007

In order to ensure safety of small vessels, the amended Ship Safety Act will come into force on 4th. Nov. 2007. This study is performed to suggest the stability criteria of fishing vessels and cargo ships of 12m in length and over but less than 24m in length which will be new object of amended Ship Safety Act. We have analyze the dimensions of domestic small vessels and the casualty reports of capsizing accidents. According to the analyzed result, 58 ships that are in the range of the dimension are modeled and the stability calculation has been carried out. The Stability for the 58 ships has been analyzed by comparing the result that applied the selected standard in the national standard to the stability calculation. Based on the regression analysis of the model ship's allowable transverse metacentric-heights under several stability requirements, stability criteria for small fishing vessels and cargo ships are proposed.

• Special Issue of the Society of Naval Architects of Korea
• /
• 2007.09a
• /
• pp.99-106
• /
• 2007

The IACS Common Structural Rules are to be applied for double hull tanker of more than 150m length with contracted after 1 April 2006. The objectives of the rules are to make more robust, safer ship and to ensure transparency of the technical background. In compliance of CSR, we had carried out prescriptive rules scantling determination and 3-D hold FE analysis of AFRAMAX TANKER. Prescriptive rules scantling determines the minimum required scantling, hull-girder longitudinal bending and shear strength, hull girder ultimate strength, local strength of plate and stiffener, strength of primary supporting member and fatigue assessment of the longitudinal stiffener end connections to the transverse bulkhead. 3-D hold FE analysis assesses the structural adequacy of the vessel's primary hull structure and major supporting members using yielding and buckling failure modes. So we could verify the strength assessment of AFRAMAX TANKER applied CSR.

• Special Issue of the Society of Naval Architects of Korea
• /
• 2007.09a
• /
• pp.14-21
• /
• 2007

A passenger ship is consist of five(5) constituents; passenger, sea, crew, port and ship itself and the rule & regulation which is applicable to passenger ship are differently required as their objects of constituents. the basic concept of rule & regulation can be defined all activities to keep safety of ship and her constituents. Especially, the rule & regulation for passenger ship design and construction shall be considered not only safety of ship itself but also safety of lives, so its are required more severe than commercial vessel. Recently, the IMO have finished the rule making work on the 'passenger ship safety' since it has been discussed last 2000 and next MSC meeting will be adopted the results. In this paper, the application method of rule & regulation are treated and the new rule which were made by IMO are introduced. The rule & regulation for passenger ship is one of the most important things. therefore, it is required to careful consideration to apply on the rule application.

• Journal of the Society of Naval Architects of Korea
• /
• v.44 no.6
• /
• pp.657-665
• /
• 2007

The object of this paper is to describe the ubiquitous computing technologies for ship, which is produced and assembled by many steel blocks. It includes the testing of a 2.4GHz wireless communications platforms and radio-frequency identification technology with the blocks disturbing the wireless communication. The power line communication that is established in a ship already is also experimented for some data transfer. Also, possible application areas of the ubiquitous computing technology to ships are discussed. At last, the test bed copied from an actual vessel was installed and data acquisition tests were established using wire and wireless communication. In this paper, we implemented some ubiquitous computing technologies in the test bed simulating a ship environment and investigated the basic characteristics of ubiquitous computing technologies.