• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.5
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• pp.552-557
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• 2015

A numerical simulation studies were performed to investigate a manoeuvring characteristics as function of stern hull form with the mathematical model. In order to consider the effect of the stern hull form and obtain the manoeuvring characteristics, a parameter($C_{wa}$) which is aft. water plane area coefficient is modified. Because modifying $C_{wa}$(${\pm}2%$) means that the stern hull form is modified to V-type or U-type, the numerical simulation was performed with this modified $C_{wa}$. A changing trend for the manoeuvring characteristics not only in deep water but also in shallow water such as directional stability, turning and zig-zag was investigated and presented as the results. Present study showed that the manoeuvrability in shallow water largely changed when the draught and water depth ratio(=d/H) become 0.5, and the stern hull form can affect to the manoeuvrability of a vessel navigating in restricted water depth. In addition, it showed that approaching the stern hull to U-type makes the advance and tactical diameter of turning motion large and the overshoot angle of zig-zag motions small. Otherwise, it showed approaching the stern hull form to V-type makes the advance and tactical diameter of turning motion small and the overshoot angle of zig-zag motions large in the present study.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.3
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• pp.328-341
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• 2010

The authors adopt the Unmanned Undersea Vehicle(UUV), which has taken the shape of manta(Sohn et al. 2006). They call here it Manta-type Unmanned Undersea Test Vehicle(MUUTV). MUUTV is designed with the similar concept of UUV called Manta Test Vehicle(MTV), which was originally built by the Naval Undersea Warfare Center, USA(Lisiewicz and French 2000, Sirmalis et al. 2001, U.S. Navy 2004). The present study deals with evaluation of extreme motion of MUUTV at large attack angles. Extreme motion contains, for example, rising and depth change due to operation of hovering thrusters attached to MUUTV, lateral motion due to ocean current applied to MUUTV at low advance velocity, and so on. Numerical simulation technique has been utilized. The previous mathematical model on manoeuvring motion of MUUTV(Bae et al. 2009a) is basically adopted. Based on the results of present model experiment on extreme motion, the mathematical model is revised and supplemented in order to describe extreme motion. The hydrodynamic derivatives related to extreme motion are obtained from present model experiment and the other derivatives are referred to previous work(Bae et al. 2009a).

• Journal of Navigation and Port Research
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• v.27 no.3
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• pp.247-252
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• 2003

This paper is mainly concerned with the assessment of safe navigation between ships moving each other in restricted waterways. The numerical simulation of manoeuvring motion was conducted parametrically to propose an appropriate safe speed and distance, which is required to avoid sea accident under the different conditions, such as ship-velocity ratios, ship-length ratios, separation and stagger between ships. As for the calculation parameters, the ratios of velocity difference between two ships were considered as 0.6, 1.2, 1.5 and the ones of ship-length difference were regarded were regarded as 0.5, 1.0, 1.18. From the inspection of this investigation, it indicates the following result. Firstly, the separation between ships is more needed for the small vessel, compared to the large vessel. Secondly, the lateral distance between ships is necessarily required for the velocity ration of 1.2, compared to the cases of 0.6 and 1.5. The manoeuvring characteristics based on this investigation will be very useful for keeping the safety of navigation from the practical point of ships design and traffic control in confined water.

• Journal of the Korean Society of Marine Environment & Safety
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• v.4 no.2
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• pp.25-33
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• 1998

This paper deals with PC-based ship handling simulator, which is now widely utilized not only for total assessment of safety in harbour area but also for training purpose. The suitable mathematical model for low advance speed manoeuvre is treated with the effects of current, wind, wave, tug force and water depth. We adopt 3 dimensional graphic technique for perspective representation of relative ship motion. Some graphical panels on the screen are devised for data input/output or ship manoeuvring information. We show the real time simulation of berthing menoeuvre applied to Pusan harbour as an example.

• Proceedings of the Korea Society for Simulation Conference
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• 2002.05a
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• pp.3-10
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• 2002

Yaw-checking and course-keeping ability in IMO's ship manoeuvrability standards is reviewed from the viewpoint of safe operation. Three types of assumed series-ships, which have systematically different instability on course, are taken as tested models. The numerical simulation on Z-test is carried out in order to examine the correlation between known manoeuvrability and various kinds of overshoot angle. Then simulator experiments are executed with series-ships in situation of curved, narrow of waterway by five pilots in order to examine the correlation between known manoeuvrability and degree of manoeuvring difficulty. Three kinds of IMO's criterion concerning yaw-checking and course-keeping ability are discussed and new criteria are proposed.

• Journal of Navigation and Port Research
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• v.30 no.5 s.111
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• pp.315-320
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• 2006

It is well known that the ship manoeuvring motion is greatly affected by hydrodynamic forces and moments acting between two vessels passing too close to each other in confined waters, such as in a harbour or narrow channel. This interaction between two vessels could be assumed to be the functions of the longitudinal distance, transverse distance and their speeds. The aim of this study is to calculate the interaction between two vessels passing close to each other on parallel courses by simulation, and to estimate the effect of rudder action and time at collision through simulation under the condition of various longitudinal distances and different speed-ratios of the two vessels.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.55-60
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• 2006

It is well known tint the ship manoeuvring motion is greatly affected by hydrodynamic forces and moments acting between two vessels passing too close to each other in confined waters, such as in a harbour or narrow channel. This interaction between two vessels could be assumed to be the functions of the longitudinal distance, transverse distance and their speeds. The aim of this study is to calculate the interaction between two vessels passing close to each other on parallel courses by simulation, and to estimate the effect of rudder action and time of collision through simulation under the condition of various longitudinal distances and different speed-ratios of the two vessels.

• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.403-412
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• 2019

The characteristics of the manoeuvring motion of a ship are dependent on the ship type, as well as draft or speed in the same ship. In recent years, the number of extra-large vessels has increased significantly, which can cause enormous material and environmental damage in the event of a marine accident. Thus, the importance of ship maneuvering is increasing. The IMO has forced the officers to be trained in simulators through the STCW 95 amendment. However, FMSS is costly and difficult to access and the PC-based simulator has the disadvantage that only one person can engage in simulation. The purpose of this study was to solve the shortcomings of the FMSS and PC-based simulators by enabling multiple people to use their PCs to simulate based on a network. The simulator is implemented through the analysis and numerical calculation of the Nomoto model, Radar function mounting, data transfer protocol design, and GUI building. To verify the simulator, the simulation results were compared and analyzed with the test results of T.S. HANBADA according to the criteria of the Korean Register of Shipping(KR) and IMO standards for ship maneuverability. As a result, It showed a relative error of 0%~ 32.1% with an average of 13.7%, and it satisfied the IMO criteria for ship maneuverability.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.3
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• pp.239-245
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• 2018

International Maritime Organization (IMO) has established standards for ship manoeuvrability and applied these standards for vessels over 100 meters in length that built since 2004 (IMO, resolution MSC.137[76]). These standards are no exception to fishing vessels. In this study we carried out a manoeuvring simulation of the new model ship (Stern trawler) of fisheries training ship of Pukyong National University based on Kijima's empirical formula. The formula takes into account of the effect of stern shape or does not take into account of the effect of stern shape. Also we checked whether the simulation results of turning motion of model ship meet IMO manoeuvrability criteria and then compared trajectories between the simulation results of model ship and the results of real sea trial test of the existing ship. In conclusion, Kijima's empirical formulas can estimate the manoeuvrability of fishing vessels at design stage approximately, it needs more parameters of fishing vessel own in case of expressing the manoeuvrability of fishing vessel accurately.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.4
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• pp.391-398
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• 2011

SHS(Ship-Handling Simulator) is virtual generation of vessel traffic situation under various environmental conditions. Recent, with the introduction of MSA(Maritime Safety Audit), SHS is being used as a key facility to determine the safety of navigation. However, the current audit techniques specified in the implementation guidance of MSA have been prepared by generalizing common procedures and evaluation methods used by institutions operating simulator systems. Therefore, they need to be reviewed and supplemented. This study analyzed the adequacy of current audit techniques based on the limitations and problems, then suggested the advanced scheme of SHS such as standardization of ship models, standard manoeuvring and evaluation method. The results of this research will contribute to improving the quantification and reliability of audit techniques used in the MSA as well as upgrading of the simulator system.