• Journal of Navigation and Port Research
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• v.37 no.3
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• pp.251-256
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• 2013

This paper is mainly concerned with the ship-bank interaction by model test. The experiments for the characteristics of hydrodynamic interaction forces and moments between vessel and bank with a mound were carried out in the seakeeping and maneuvering basin. A series of tests were carried out with ship model in parallel course along a vertical sidewall with a mound with varying lateral spacing between model ship and sidewall, length of sidewall and water depth. From the experimental results, it indicated that the hydrodynamic interaction effects increase as length of sidewall with a mound increases. Furthermore, for lateral spacing less than about 0.2L between vessel and bank, it can be concluded that the bank effects increase largely as the lateral spacing between vessel and bank decreases. However, for spacing between vessel and bank more than about 0.3L, the interaction effects increase slowly as lateral spacing decreases. Also, for the water depth to draft ratio(h/d) less than about 1.5, the hydrodynamic interaction effects increase dramatically as h/d decreases.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.2
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• pp.88-94
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• 2013

The primary objective of the current work is to obviously analyze regarding effects of trim conditions of a ship on resistance performance using model test and CFD. Model tests at a towing tank are conducted to investigate resistance for trim conditions at the given same displacement. Measured resistance shows small but distinct differences according to trim conditions. However, these differences are difficult to be clarified by measured physical quantities and wave pattern analysis from model tests. CFD is employed for the assessment of resistance performance according to trim conditions. The flow computation is conducted considering free surface and dynamic trim using a commercial CFD code (STAR-CCM+). The initiative of the present work is to systematically demonstrate pressure resistance acting on each region of divided finite zones of ship surface along the length and draught direction of surface when pressure distribution on the ship is interpreted. Also, a standard to assess the pressure resistance applied on the divided regions of a ship is established.

• Journal of Ocean Engineering and Technology
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• v.24 no.2
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• pp.74-81
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• 2010

Ship STEP is the international standard for the exchange of ship modeling data between heterogeneous systems. It is expected that STEP AP218 can be used for seamless data exchange between various CAD/CAM/CAE systems used in the shipbuilding design process. Although the conformance assessment for standards would maximize the performance and confidence about data exchanges, most research has been directed toward interoperability testing. ISO SC4/TC184 only provides the method for conformance testing, and it can be used with test cases on application protocols. Even though standards have been defined for conformance assessment and testing, there is no organization or association. CAD vendors have focused on interoperability testing for evaluation of the performance of their systems. In this paper, the conformance testing criteria for AP218 have been developed with abstract test cases of ship structures. The requested STEP translator was also reviewed with a developed item pool of testing criteria. The criteria methodology would be a guideline for the development of translators and interfaces. The item pool method of testing criteria for conformance assessment would increase performance and efficiency of data translators for Ship STEP and other standards.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.6
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• pp.504-511
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• 2012

The objective of this study is to investigate tank container to be used as fuel tank for LNG fueled ship. Feasibility of tank container to the fuel tank of LNG fueled ship is addressed and the advantage of tank container as fuel tank of ship is investigated. Conceptual configuration of the tank container is designed as well as structural analyses based on finite element method are carried out to meet the design regulation suggested by shipping register. Static loading is considered by structural analysis and impact test is performed. It is necessary to require SRS(shock response spectrum) in order to investigate structural safety which can meet.

• Journal of Navigation and Port Research
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• v.33 no.2
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• pp.99-104
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• 2009

The Kinematic GPS is well known to provide a quite good accuracy of positioning within an level. Although kinematic GPS assures high precision measurement on the basis of an appreciable distance between a reference station and an observational point, it has measurable distance restriction within 20 km from a reference station on land. Therefore, it is necessary to make out a simple and low-cost method to obtain accurate positioning information without distance restriction In this paper, the velocity integration method to get the precise velocity information of a ship is explained. The experimental results of Zig-zag maneuver and Williamson turn as the ship's maneuvering test, and other experimental results of ship's movement during leaving and entering the port with low speed were shown. From the experimental results, ship's course, speed and position are compared with those obtained by kinematic-GPS, velocity integration method and dead reckoning position using Gyro-compass and Doppler-log.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.1
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• pp.46-53
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• 1998

In this paper, we studied to improve Inoue's[1] and Kijima's[2] model used to predict ship's manoeuvrability at initial design state. To perform this work, we carried out PMM(Planar motion Mechanism) test and rudder open water test for 12 models of low-speed blunt-ship which have horn type rudders and bulbs in afterbody. As we adopted MMG(Mathematical Modelling Group) model, we could analyze hydrodynamic and MMG experimental coefficients. The regression analyses by principle parameters were carried out for hydrodynamic and MMG experimental coefficients. The regression analyses by principle parameters were carried out for hydrodynamic and MMG experimental coefficients and the equations by regression analysis wee used to search sensitivities and to estimate ship's manoeuvrability. We had simulated ship's manoeuvrability to check revised MMG.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.05a
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• pp.98-100
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• 2019

In the past, there were several researchers investigating waves generated by a small boat. Wave generated by a ship can be divided into two distinct systems of waves, such as transverse and diverging waves. It is necessary to understand the behavior of a ship in waves generated by a small boat near port in the view point of ship safety. In this study, the motion of moored floater in waves generated by a small boat near port is investigated. The model test is performed in waves in a square tank in Changwon National University (CWNU). IMU and optical-based system which uses the technique of recording and capturing attitude with respect time are used for measuring 6DOF motion of the moored floater. In addition, tension gauges are used to measure the tension of mooring lines. The effect of waves generated by a small boat on motion of the moored floater near port is investigated through performing the model test in various wave directions of virtually but reasonably assumed wave scenarios.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.6
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• pp.407-414
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• 2021

The manoeuvrability of a ship with an unwanted heel angle due to a maritime accident is changed from the original characteristics. The purpose of this study is to quantitatively investigate the change in the manoeuvring performance of a twin-screw ship under various hee angles and speed conditions. A series of free running model test campaigns were performed in the Ocean Engineering Basin of Korea Research Institute of Ships & Ocean Engineering (KRISO) for a twin-screw car ferry vessel. Turning circle test and zig-zag 10/10 and 20/20 tests were carried out on the heel angles of 0, -10, and -19.5 degrees. In addition, two-speed conditions were considered to understand the effect of ship speed. In order to examine the effect of the bilge keel, a heel angle of -22 degree where the bilge keel is exposed outside the water surface, was considered. Finally, the change of manoeuvring characteristics according to the heel angle for a twin-screw and a single-screw vessel is discussed.

• Journal of Ocean Engineering and Technology
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• v.37 no.1
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• pp.38-48
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• 2023

To maintain the existing systems of ships and introduce autonomous operation technology, it is necessary to improve situational awareness through the sensor fusion of the automatic identification system (AIS) and automatic radar plotting aid (ARPA), which are installed sensors. This study proposes an algorithm for determining whether AIS and ARPA signals are sent to the same ship in real time. To minimize the number of errors caused by the time series and abnormal phenomena of heterogeneous signals, a tracking method based on the combination of the unscented Kalman filter and probabilistic data association filter is performed on ARPA radar signals, and a position prediction method is applied to AIS signals. Especially, the proposed algorithm determines whether the signal is for the same vessel by comparing motion-related components among data of heterogeneous signals to which the corresponding method is applied. Finally, a measurement test is conducted on a training ship. In this process, the proposed algorithm is validated using the AIS and ARPA signal data received by the voyage data recorder for the same ship. In addition, the proposed algorithm is verified by comparing the test results with those obtained from raw data. Therefore, it is recommended to use a sensor fusion algorithm that considers the characteristics of sensors to improve the situational awareness accuracy of existing ship systems.

• International Journal of Naval Architecture and Ocean Engineering
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• v.2 no.3
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• pp.139-145
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• 2010

In the present study, we conducted resistance test, propeller open water test and self-propulsion test for a ship's resistance and propulsion performance, using computational fluid dynamics techniques, where a Reynolds-averaged Navier-Stokes equations solver was employed. For convenience of mesh generation, unstructured meshes were used in the bow and stern region of a ship, where the hull shape is formed of delicate curved surfaces. On the other hand, structured meshes were generated for the middle part of the hull and the rest of the domain, i.e., the region of relatively simple geometry. To facilitate the rotating propeller for propeller open water test and self-propulsion test, a sliding mesh technique was adopted. Free-surface effects were included by employing the volume of fluid method for multi-phase flows. The computational results were validated by comparing with the existing experimental data.