• Journal of the Society of Naval Architects of Korea
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• v.40 no.4
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• pp.37-45
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• 2003

Model tests using 2.0m model of the series 60 form( $C_{b}$= 0.6) were carried out in the Circulating Water Channel (CWC) in the Chosun University (CU, Korea) for the purpose of a correlative study with Towing Tank (TT). Resistance, propeller open water, self propulsion and wake survey tests were carried out and the results were extrapolated to the ship scale. These results were compared with the extrapolated ship values based on the model test of 7.0m model in the TT at the Korea Research Institute of Ships and Ocean Engineering (KRISO, Korea). The CWC test results were correlated with the results of the towing tank tests.s.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.4
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• pp.109-115
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• 2011

The ice tank is important facility to check the performance of the ship and offshore in ice condition before the construction. MOERI(Maritime & Ocean Engineering Research Institute) constructed ice model basin on the end of 2010. The ice technology to know the phenomena of ice near the ship and to estimate power of the ship in model scale is the main characteristic of the ice model basin. To achieve this goal in one ice sheet, making of test plan and feasibility check of test possibility have to review in the beginning stage of the every test. This paper describes the number of maximum resistance and self propulsion test in a sheet of level ice and proposes the methodology to optimize pack ice, rubble ice, brash ice and ice ridge test in MOERI ice tank. The feasibility of free running test to know maneuvering performance in ice field and some specific idea to measuring ice thickness and ice ridge shape was proposed.

• International Journal of Ocean System Engineering
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• v.3 no.2
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• pp.77-89
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• 2013

The propeller performance has been investigated using a benchmark Duisburg Test Case ship with RANSE. First, the hydrodynamic characteristics of propeller in case of open water have been analyzed by a commercial CFD program and the results are compared with those of experimental data. Later, the flow around the bare hull has been solved and the frictional resistance value and form factor of the ship have been obtained and compared with those of ITTC57 formulation and experimental results for validation. The free surface effect has been ignored. A good agreement has been obtained between the results of RANSE and experiments at both stages. Then the ship - propeller interaction problem was solved by RANSE and the differences in thrust, torque and efficiency of propeller as compared with the open-water numerical results have been discussed.

• Journal of Ocean Engineering and Technology
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• v.29 no.2
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• pp.111-119
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• 2015

In the initial ship design stage, performance predictions are generally carried out before and after the hull form design. The former is based on the main dimensions and power information, and the latter is based on the geometry of the hull form and propeller. This paper deals with the practical application of neural networks for the prediction of a ship's performance factors before and after the hull form design. For this, the hull form parameters that affect the performance are studied, and an optimal neural network structure based on the SSMB database is constructed. By comparing the results predicted by neural networks and the model test results, we confirmed that neural networks can be applied to practically evaluate the performance in the initial ship design stage.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.843-855
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• 2020

X-plane submarines show better maneuverability as they have much longer span of control plane than that of cross plane submarines. In this study, captive model tests were conducted to evaluate the maneuverability of an X-plane submarine using Computational Fluid Dynamics (CFD) and a mathematical maneuvering model. For CFD analysis, SNUFOAM, CFD software specialized in naval hydrodynamics based on the open-source toolkit, OpenFOAM, was applied. A generic submarine Joubert BB2 was selected as a test model, which was modified by Maritime Research Institute Netherlands (MARIN). Captive model tests including propeller open water, resistance, self-propulsion, static drift, horizontal planar motion mechanism and vertical planar motion mechanism tests were carried out to obtain maneuvering coefficients of the submarine. Maneuvering simulations for turning circle tests were performed using the maneuvering coefficients obtained from the captive model tests. The simulated trajectory showed good agreement with that of free running model tests. From the results, it was proved that CFD simulations can be applicable to obtain reliable maneuvering coefficients for X-plane submarines.

• Special Issue of the Society of Naval Architects of Korea
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• 2013.12a
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• pp.42-46
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• 2013

Recently, according to the growth of demand about large container carrier, the studies for cavitation of semi-spade rudder were increased. In spite of many effort to solve, the fundamental solution can not be found. So, the studies for full-spade rudder are increasing to solve. In Pusan national university, the studies for full-spade twisted rudder and full-spade wavy twist rudder were carried out. However, most studies are carried out in numerical analysis and the many studies of experimental comparison between each rudder are not exist. This paper describe design history of full-spade rudder (twist rudder, wavy twist rudder) for KCS (KRISO Container Ship) and compare performance of each designed full-spade rudder about resistance and self-propulsion with conventional rudder (semi-spde rudder). The measurement about designed rudder's rudder force will be performed near future.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.6
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• pp.20-29
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• 2003

When Arctic offshore development in the 1970's first led to the consideration of ice capable tankers, there was a high level of uncertainty over design requirements for both safety and ship performance. Also here was a lack of reliable methods to evaluate design proposals. Since that time, improved understanding of the ice environment has raised the confidence of design specifications. Parallel developments have resulted in a suite of engineering tools for ship performance evaluation at the design stage Recent development of offshore and near shore oil and gas reserves in several countries together with economic studies of increased transportation through the Russian Arctic has newly introduced the interest in ice capable tanker design. in response, Samsung Heavy Industries (SHI) applied its experience in tanker design and construction to the design of a specialized tanker with ice capability. SHI produced two prototype hull designs for further study. The performance of both hulls and of the propellers was evaluated at the Institute for Marine Dynamics (IMD) in St. John's, Newfoundland This paper discusses the development of the design, describes the model experiments to determine performance and variations, and presents the results.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.3
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• pp.198-205
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• 2021

In this paper, the effect of trim variation on the required power of 11,000TEU container ship was investigated under conditions considering the actual operation speed and draft. For each draft condition, the effective power (P_E) and delivered power (P_D) trends were investigated with changes in trim and ship speed. At this time, the displacement volume was fixed same as the value of the even trim condition and the both sinkage at the fore and after perpendicular are confirmed. The test ship speeds were determined by considering the operating speed. Both numerical and experimental methods were used to analyze the effects of trim variation. Numerical analysis results were used for evaluating the resistance performance, and the self-propulsion performance was estimated using experimental data obtained from model test.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.1
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• pp.1-9
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• 2023

In order to improve the propeller cavitation performance composed of Cavitation Inception Speed (CIS), cavitation extent and pressure fluctuation, it needs to improve the wake distribution that flows into the propeller. The warship propeller cavitation is strongly influenced by the wake created at the V-strut of various appendages. The inflow characteristics of the V-strut were investigated using Computational Fluid Dynamics (CFD) and the twisted angles of the V-strut were aligned with upstream flow. The resistance and self-propulsion tests for the model ship with the existing and modified V-struts were conducted in Towing Tank (TT), and wake distribution, CIS, cavitation observation and pressure fluctuation tests were conducted in Large Cavitation Tunnel (LCT). The propeller behind the modified V-strut showed better cavitation characteristics than that behind the existing V-strut. Another model test was conducted to investigate rudder cavitation performance by the change of the V-strut. The rudder cavitation characteristics were not improved by the change of the operating conditions. On the basis of the present study, it is thought that the stern appendages for better propeller cavitation performance would be developed.

• Journal of the Society of Naval Architects of Korea
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• v.37 no.3
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• pp.11-20
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• 2000

The flow characteristics around the stern region of two VLCCs with the same forebody and slightly different afterbody are investigated along with propulsive performance of the ship. The local mean flow measurements and the resistance and self-propulsion tests are carried out in the towing tank for the two VLCC hull forms. The measured results clearly show the formation of bilge vortices and their effect on propulsive efficiency. The comparisons are made for the two VLCC hull forms and the relation between stern framelines and bilge vortex strength is explored. Experimental data can provide a good test case to validate the accuracy of numerical methods and turbulence model of CFD codes for ship flow calculation.