• Title/Summary/Keyword: Towing tank

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Collision Test between Ice Floe and Ship Transiting the Pack Ice

  • Kim, Hyo-Il;Sawamura, Junji;Jun, Seung-Hwan
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2015.10a
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    • pp.37-39
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    • 2015
  • The ships transiting the Northern Sea Route (NSR) have been gradually increased so that the number of ship-ice collision accidents would be increased. The collision between ship and ice floe can lead to serious damage of hulls and decline of ship's maneuverability. In this study, collision tests that a model ship is forced to collide with disk-shaped synthetic ice floes are conducted in a towing tank. The synthetic ice floes made of polypropylene which has similar density with real ice are used. The ice load is measured by a load cell installed on the carriage rod. The ice floe's motion is measured by a motion sensor installed on the synthetic ice floe. The influences of contact conditions such as hull form and ship speed on the ship-ice collision response are investigated and discussed by measured peak force and ice floe's motion.

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Hull Form Improvement of a Tuna Longliner for the Northern Pacific Ocean (북양조업(北洋操業) 가다랭이 연승어선(延繩漁船)의 선형개량(船型改良)에 관한 실험적(實驗的) 연구(硏究))

  • Wu-Joan,Kim;Suak-Ho,Van;Young-Min,Park;Hyo-Chul,Kim
    • Bulletin of the Society of Naval Architects of Korea
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    • v.25 no.1
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    • pp.47-55
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    • 1988
  • One of tuna longliners which have excellent operational record at the tropical Pacifical Ocean was selected as a parent hull form for the development of a new ship which could be operate at the high latitude northern Pacific Ocean. The parent hull was modified to adapt operational and enviromental condition of such a weather and sea states. This modification was carried out based on design experiences and model test results in towing tank. In this report modification techniques applied to the hull form design of a tuna longliner are summarized. The powering performance of the developed hull form is evaluated to show 19%, decrease of resistance campared with the parent hull form.

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A Comparison of Hydrodynamic Characteristics of Single and Tandem Strut SWATH Ships (하나 또는 두개의 지주를 갖는 소수선면 쌍동선의 유체동역학적 특성 비교)

  • Ho-Hwan Chun
    • Journal of the Society of Naval Architects of Korea
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    • v.29 no.3
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    • pp.102-116
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    • 1992
  • This report is to provide a comparison of the hydrodynamic characteristics of a single strut SWATH(Small Waterplane Area Twin Hull) model and a tandem(twin) strut SWATH model. The hydrodynamic characteristics included are the resistance in calm water, 6 degree freedom of motion responses in stationary and with forward speeds, and wave loadings etc. All these quantities are measured in the towing tank and compared with the computational results. Based on the present study, the pros and cons for single and tandem strut SWATH designs are clarified and some design suggestions are made.

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Measurement of flow around KRISO 138K LNG Carrier Model (KRISO 138K LNG 운반선 모형 주위의 국부 유동장 계측)

  • 반석호;윤현세;이영연;박일룡;이춘주;김우전
    • Journal of the Society of Naval Architects of Korea
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    • v.40 no.2
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    • pp.1-10
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    • 2003
  • It is important to understand the flow characteristics such as wave and wake development around a ship for the design of the hull forms with better resistance and propulsive performance. The experimental results explicating the local flow characteristics are also invaluable for validation of the physical and numerical modeling of CFD codes, which are recently gaining acknowledgements as efficient tools for hull form evaluation This paper describes velocity and wave profiles measured in the towing tank for the KRISO 138K LNG Carrier (KLNG) model with propeller and rudder. The results contained in this paper can provide the valuable information on the effect of propeller and rudder on stern flow characteristics of the modern commercial hull form, furthermore, the present experimental data will provide important database for CFO validation.

Correlation Analysis of Model Tests with Ship Powering Data for a 60,000 DWT Bulk Carrier (6만 DWT 산적화물선(散積貨物船) 모형선-실선(模型船-實船) 상관해석(相關解析))

  • Seung-Il,Yang;Chang-Sup,Lee;Eun-Chan,Kim
    • 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.

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Application of Coanda Effects to a Ship Hydrofoil

  • Oh, Jung-Keun;Ahn, Hae-Seong;Kim, Hyo-Chul;Lee, Seung-Hee;Lew, Jae-Moon
    • Journal of Ship and Ocean Technology
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    • v.7 no.2
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    • pp.29-39
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    • 2003
  • A Coanda foil is a high-lift generating device exploiting the phenomena that flow separation is delayed if a high-speed jet is applied tangential to the surface as well known to the aerodynamic fields. In the present study, a Coanda foil with a flap is investigated to seek the possibility of marine application. Model experiments are carried out both in a towing tank and cavitation tunnel and surface pressure distributions, forces and moments acting on the foil are measured at the various angle of attacks and flap angles. The results are also compared to the numerical ones to show good agreements. The results of the present study demonstrate the practical applicability of the Coanda foil in the design of ship control surfaces.

Development of a Stability System to prevent a Capsize of a Small Fishing Vessel (소형어선의 전복방지화 안정장치 시스템 개발에 관한 연구)

  • Cheon, Seung-Hyeon;Jeon, Ho-Hwan;Kim, Chang-Hun;Kim, Si-Yeong;,
    • Journal of Ocean Engineering and Technology
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    • v.13 no.1 s.31
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    • pp.130-137
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    • 1999
  • The wing-flap stabilizing system attached under the hull bottom of a small fishing vessel to prevent the capsize by controlling the roll motions has been developed. This paper describes the background of the system design together with the experimental results. The effectiveness of the system is proven by the towing tank tests with a 1/4 scale model, showing that the roll motions of the model are much reduced by the active flap control in multidirectional irregular waves forward speeds.

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A Study on the Possibility of Hull Form Design using Numerical Towing Tank (SHIPFLOW)

  • Lee, Kwi-Joo;Joa, Soon-Won;Sun, Jae-Ouk
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.251-253
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    • 2003
  • This paper discusses some practical problems of the determination of ship wave resistance from flow calculation and the model test. there are so many kind of CFD program as FLUENT, WAVIS, SHIPFLOW, COMET etc. for finding optimized hull. we should know how much percent we trust the program. so if we gather computed values of the wave resistance we'll able to get more accurated values of presumptive.

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An Experimental Study on Hull Attitude and Resistance Components of a Ship (선박의 항주자세와 저항성분에 관한 실험적 연구)

  • Suak-Ho,Van;Hyo-Chul,Kim
    • Bulletin of the Society of Naval Architects of Korea
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    • v.24 no.2
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    • pp.11-19
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    • 1987
  • A Series 60, $C_b=0.60$ model was tested in the towing tank of Seoul National University. Total resistance, hull attitude, wake distributions and wave measured at FR condition(free trim and sinkage) and FX condition(fixed trim and sinkage). From the measured data, residual, viscous and wave pattern resistance components were evaluated and compared. It is found that the changes in wetted surface area should be considered in predictions of frictional resistances, and can be easily found from hydrostatic data and measured mean sinkages without additional tests. Applications of the concept to the geosim tests of Series 60, Wigley, Lucy Ashton models show that the conventional extrapolation method can be improved considerably.

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Hull Form Optimization of a Small Trimar:an by Model Testing

  • Oh Se-Myun;Lee Seung-Hee;Lee Young-Gill
    • 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.