• Journal of the Society of Naval Architects of Korea
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• v.44 no.4
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• pp.389-397
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• 2007

This research describes a framework to compare and analyze the icebreaker(Terry Fox) resistance in pack ice condition between with a refrigerated ice and a synthetic ice. Model tests with a refrigerated ice have been conducted at Institute for Ocean Technology (IOT/NRC) and the tests with a synthetic ice were conducted at Pusan National University towing tank. For the validation of further tests of measurement and accuracy, the open water tests were first carried out with same model ship to compare the test results of both Institutes. Two different size of the wax-type synthetic ice were used and tests were conducted in pack ice of three different concentration ice conditions. The test results show that the difference of resistance between with synthetic and with refrigerated ice becomes larger according to the increase of ship speed. Although the quantity of resistance difference is not so small in high speed range, the present study is predicted to be used as a useful correlation between synthetic and refrigerated ice.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.4
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• pp.240-247
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• 2013

Hydrodynamic characteristics of a planing craft are very sensitive to the hull form variations, especially when the craft navigates with high-speed. Therefore, we need to verify hydrodynamic performances of the craft during the process of hull form design. In this paper, motion performances of a 40ft class cruise leisure boat are evaluated by both model tests and theoretical analyses using two different methods. Model tests are carried out at calm sea and regular wave conditions using high speed towing carriage installed in SNU towing tank. Theoretical methods used are a empirical method proposed by Martin (1976) and a potential method based on Rankine panel (DNV, 2010). The results from the theoretical methods are compared with and verified by those of model tests. Results of empirical formula showed somewhat larger motion RAOs and resonant frequencies than those of model tests. Potential based method showed even larger discrepancies with the model test results. From the analyses of comparison results, we could confirm the limitation of each theoretical method and suggest the way of improvement for the better prediction of motion performances.

• Bulletin of the Society of Naval Architects of Korea
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• v.19 no.4
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• pp.61-70
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• 1982

The hydrodynamic effects on resistance and propulsive performance were studied by using the data from model test and full scale speed trials. A series of model tests on 3 geosims for a 60,000 DWT Bulk Carrier was conducted at KIMM's Ship Experimental Towing Tank and the results analyzed by 1978 ITTC Performance Prediction Method show the correlation between 3 geosim models. Also powering data of full scale speed trials were analyzed by the newly developed computer program and the correlation analysis between ship and model was studied.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.4
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• pp.316-322
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• 2017

The primary objective of the current study is to develop outstanding hull form on resistance performance by using numerical analysis code. Model tests were conducted to assess the resistance performance of the developed hull form. The investigation of an existing vessel was performed for validating the actual ship design based on the drawing. The operating displacement and speed were mainly confirmed through investigation of the existing vessel. The resistance performance of the existing vessel was analyzed using numerical code. The developed vessel was derived through studies on wave improvement of the bow shoulder, the balance of displacement distribution, the modification of the frame shape, and the size and shape change of the center skeg. Based on the results of a computational fluid dynamics analysis, the resistance performance of the developed vessel showed an improvement of 15% over the existing vessel at a speed of 11 knots. Resistance tests were conducted to evaluate the performance of the existing vessel and the developed vessel in the towing tank. Finally, the effective horsepower of the developed vessel showed an improvement of 17% over the existing vessel.

• Journal of Ocean Engineering and Technology
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• v.22 no.3
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• pp.64-70
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• 2008

A full-scale field experiment is an important part in the design of ships and offshore structures. Full-scale tests in the ice-covered sea, however, are usually very expensive and difficult tasks. Model tests in a refrigerated ice tank may substitute this difficulty of full-scale field tests. One of the major tasks to perform proper model tests in an ice towing tank is to select a realistic material for model ice which shows correct similitude with natural sea ice. This study focuses on the testing material properties and the selection of model ice material which will be used in an ice model basin. The first Korean ice model basin will be constructed at the Maritime & Ocean Engineering Research Institute (MOERI) in 2009. With an application to the MOERI ice model basin, in this study the material properties of EG/AD/S model ice of IOT (Institute for Ocean Technology) Canada, were tested. Through comprehensive bending tests, the elastic modulus and the flexural strength of EG/AD/S model ice were evaluated and the results were compared with published test results from Canada. Instead of using an ice model basin, a cold room facility was used for making a model ice specimen. Since the cold room adopts a different freezing procedure to make model ice, the strength of the model ice specimen differs from the published test results. The reason for this difference is discussed and the future development for a making model ice is recommended.

• Journal of Ship and Ocean Technology
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• v.9 no.3
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• pp.14-22
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• 2005

A 12 m long G/T 4.99 Class Trimaran is now under development at the Center for Transportation System of the Yellow Sea (CTYS) before deployed as a pleasure fishing boat along the west coast of Korean peninsula. The boats will be made of fiber reinforced plastics and equipped with a 360 hp diesel engine and a water jet propulsion system to propel the ship to reach maximum speed of 25knots after fully loaded. Model tests for hull form development of the Trimaran have been done at the towing tank of the Inha University. The influence of the spacing between main hull and outriggers and the longitudinal location of the outriggers have been carefully examined to find the optimal size and locations of the outriggers to improve both the resistance characteristics, and the results are reported in the present paper.

• Journal of Hydrospace Technology
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• v.2 no.2
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• pp.68-79
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• 1996

The present report describes the results of the cooperative experimental study organized by the High-Speed Marine Vehicle Committee of the Korea Towing Tank Conference. The study aims to improve model test technique and accuracy and to self-evaluate their own capabilities. The resistance tests of a 23m class planing hull were performed at the towing tanks of the Korea Research Institute of Ships and Ocean Engineering (KRISO), Hyundai Maritime Research Institute (HMRI), Seoul National University (SNU), Inha University (IU) and Pusan National University (PNU). In addition, the longitudinal wave cut was measured antral and analyzed at the KRISO. All the results of total resistance, trim and mean sinkage are presented in this report and the results show fairly good agreements comparing with the ITTC HSMV committee's report.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.4
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• pp.373-381
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• 2009

The running attitude of a high-speed planing craft may change significantly depending on its speed in seaway. Other variables that may influence its running attitude are its weight, center of gravity, sea conditions, and so on. In this paper, planing craft model tests were carried out with respect to above variables in SNU towing tank, and vertical motion responses of a planing craft in regular head waves were analyzed. The experimental results in regular waves were compared with those in calm water, and compared with the theoretical estimations. Finally, the effects of running speeds of a planing craft on its motion amplitudes are confirmed.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.6
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• pp.120-125
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• 2004

There are very few numbers of 115K FPP (Fixed Pitch Propulsion) Tankers for the Baltic ice class IA because the minimum power requirement of FMA (Finish- Swedish Maritime Association) needs quite large engine power and the 40 m Beam is out of calculation range of FMA minimum power requirements. The shipyard has no choice except to increase the engine power to satisfy FMA minimum power requirement Rule. And the operation cost, efficiency of hullform and its building cost are not good from the ship owners' point of view To solve this problem, the experience of ice breaking tanker development and the ice tank test results were adopted. The main idea to reduce the ice resistance is by reducing waterline angle at design load waterline. The reason behind the main idea is to reduce the ice-clearing force. Two hull forms were developed to satisfy Baltic Ice class IA. Two ice tank tests and one towing tank test was performed at MARC (Kvaener-Masa Arctic Research Center) and SSMB (Samsung Ship Model Basin) facilities, respectively. The purpose of these tests was to verify the performance in ice and open water respectively The hull form 2 shows less speed loss compared to Hull form 1 in open water operation but hull form 2 shows very good ice clearing ability. finally the Hull Form 2 satisfying Baltic ice class IA. The merit of this hull form is to use the same engine capacity and no major design changes in hull form and other related designs But the hull structure has to be changed according to the ice class grade. The difference in two hull form development methods, ice model test methods and analysis methods of ice model test will be described in this paper.

• Journal of Navigation and Port Research
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• v.34 no.8
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• pp.623-628
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• 2010

High speed marine vehicle, such as semi-planing, planing craft have been developed recently. These ships paid attention to the resistance characteristics, especially in high speed region. Model test method is divided to two equipment greatly, first 'Towing tank', second 'C.W.C.'. It is difficult to estimate a resistance characteristics for high speed boat. because these are made for low speed ship. This paper suggests a new model test method and system. This is real sea model test and it's comprised of eight part. Firstly, This method is tested at C.W.C that is possible to using in real sea model tes using low speed boat modelt. And then, Real sea model test and CFD calculation are performed and compared with tow way used high speed boat model. It can be a good way to estimate a performance for high speed boat.