• Title/Summary/Keyword: Heeling

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A Study on the Effect of Wind Force and Moment Acting on T/S HANNARA (실습선 한나라호에 작용하는 풍압력 및 풍압모우멘트 영향에 관한 연구)

  • Lee, Yun-Sok
    • Journal of Navigation and Port Research
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    • v.31 no.3 s.119
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    • pp.223-228
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    • 2007
  • In recent trends of the enlargement and specialization, container ship, LNCG, PCC and passenger ship which have relatively large hull and superstructure above the water line, are already being operated in the world It is very important information for the safety operation of these vessels to estimate the ship's performance under the specific wind condition while berthing, unberthing or low-speed sailing. In this paper, the effect of wind force and moment acting on the training ship HANNARA is investigated by using the numerical calculations. The results of drift angle and counter rudder angle with the relative wind direction and force, the critical wind velocity with the ratio of wind velocity and ship's speed and maximum heeling angle with the wind velocity are shown The presented results can be applied directly to T/S HANNARA in berthing maneuver and avoiding typhoons, and utilized as an educational materials.

Performance Predictions for Sailing Yacht by Towing Tests and VPP Calculation (예인수조 시험 및 VPP 계산에 의한 세일링 요트의 성능 추정)

  • Yoo Jae-Hoon;Ahn Hae-Seong
    • Journal of Advanced Marine Engineering and Technology
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    • v.30 no.1
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    • pp.116-124
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    • 2006
  • A model test was carried out, in order to verify the hydrodynamic performances of public 30 feet class sailing yacht. In the initial design stage, the performances and the running attitude of sail yacht including the hull form and sail plan, appendages were estimated by VPP, from which made the representative test conditions. A new experiment system such as captive model device was composed because the running attitude could be changed by wind conditions. The test results show that the minimum resistance is generated in the heeling 20 degree. which was expected in the initial design stage. It is thought to be the useful informations that the keel has an effects on hydrodynamic forces and resistance differences between the upwind and the downwind condition. Also this paper is associated with the state-of-the-art of calculating sailing yacht performance as this is performed in velocity Prediction program (VPP) The VPP results shows a typical shape of a sailing yacht and the designed yacht has the best performance at 120 degree angle of true wind with 20 knots.

Analysis of Electromagnetic Vibration Sources in 100kW Interior Permanent Magnet Motor (100kW급 IPM 전동기의 전자기 가진력 분석)

  • Lee, Sun-Kwon;Kang, Gyu-Hong;Hur, Jin
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.953-954
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    • 2011
  • 본 논문에서는 선박의 Rolling 현상을 능동적으로 저감할 수 있는 Anti heeling system에 적용되는 100kW급 매입형 영구자석 전동기의 가진력을 2차원 FEA를 이용하여 해석하였다. 고효율 소형화를 위해 집중권을 채택했고, 극수 슬롯수 조합에 따른 특성을 비교하였다. 타발작업 및 조립작업 시 편심은 항상 발생하게 되고, 그 수준과 형태에 따라 다양한 Unbalanced magnetic force(UMF)가 발생하여 진동특성에 영향을 미친다. 8극 12슬롯과 10극 12슬롯 구조의 여러 가지 편심조건에 따른 UMF를 비교하였으며, 진동 실험을 통해 해석결과의 타당성을 검증하였다.

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A System for Rapid Design and Manufacturing of Custom-Tailored Shoes

  • Park, Sang-Kun;Lee, Kun-Woo;Kim, Jong-Won;Park, Jong-Woo
    • Journal of Mechanical Science and Technology
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    • v.14 no.6
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    • pp.675-689
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    • 2000
  • Rapid design and production techniques are indispensable for the custom-made production systems. For manufacturing custom-made shoes, the shoelast should be designed rapidly from the individual foot model. In this paper, we develop an integrated system for rapid design and manufacturing of custom-tailored shoes. The foot shape measurement sub-system allows scanning a standard shoelast and an individual foot and then extracts the three-dimensional crosssectional data of the shoelast and the human foot shape from the captured image data. The shoelast design sub-system uses the scanned data to design new customized shoelast curves or surfaces with the heeling and mixing algorithms built in this system. The pattern design subsystem provides a method, which transforms a shoe-upper surface designed by a stylist into a flat-pattern that can be manufactured. We also export the surface model to an NC machine to manufacture the physical shoelast model.

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A Study for Stability Criteria of Small Fishing Vessel (소형어선 복원성 판정 기준에 관한 연구)

  • 박제웅;김주남;허진호
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.5 no.2
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    • pp.45-55
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    • 1999
  • The majority of fishing vessels(under 20 tonnages) in Korea have a high casualty accident of the flood and capsizing occurred by lack of stability. Actually, it is so difficult to make out the data of inclining and stability tests of small fishing vessels after building, because most of them were built on experiences of manufacturer. According to above reasons, the aim of this study is an attempt to propose a stability criteria of small fishing vessels as follows: Firstly, it is examined that the stability is driven from a transverse metacenter height of actual ships, which is able to obtain a basic drawing and stability data. Secondly, it is examined the heeling at high-speed turning, and the period of rolling according to B/D(breadth/depth). Finally, it is suggested the stability criteria by using a dynamic state which is applied in passenger boat and fishing vessels over 24 meters.

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Hydrodynamic Forces and Flow Characteristics for Three-Different Types of Yacht Keel (요트 킬의 형상에 따른 유체력 및 유동특성 연구)

  • Choi, Ki-Chul;Hyun, Beom-Soo
    • Journal of the Society of Naval Architects of Korea
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    • v.43 no.4 s.148
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    • pp.414-421
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    • 2006
  • Yacht is operated by wind-driven thrust on the saii, but also experiencing the side force. Thus the keel attached on the bottom of main hull prevents it from flowing sideway. Since the keel affects the stability and thrust of yacht, its selection is one of the most important factor in design. In the present paper the correlation between yacht hull and keel was investigated. through comparison of forces measured at various combinations of heeling and leeway angles with and without keel. Keel-only test was also performed to find out the drag and lift characteristics of keel itself. finally three different types of keel, i.e. fin keel, bulb keel and winglet keel were tested to compare their advantages and drawbacks.

Performance Predictions for Sailing Yacht (세일링 요트의 성능 추정에 관한 연구)

  • Yoo, Jae-Hoon;Ahn, Hae-Seong
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.06a
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    • pp.824-831
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    • 2005
  • A model test was carried out, in order to verify the hydrodynamic performances of public 30 feet class sailing yacht. In the initial design stage, the performances and the running attitude of sail yacht including the hull form and sail plan, appendages were estimated by VPP, from which made the representative test conditions. A new experiment system such as captive model device was composed because the running attitude could be changed by wind conditions. The test results show that the minimum resistance is generated in the heeling 20 degree, which was expected in the initial design stage. It is thought to be the useful informations that the keel has an effects on hydrodynamic forces and resistance differences between the upwind and the downwind condition. Also this paper is associated with the state-of-the-art of calculating sailing yacht performance as this is performed in velocity prediction program (VPP). The VPP results shows a typical shape of a sailing yacht and the designed yacht has the best performance at 120 degree angle of true wind with 20 knots.

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Experimental Study on the Hydrodynamic Forces of 30 Feet Sailing Yacht (30피트급 요트의 유체력에 대한 실험적 연구)

  • Yoo, Jae-Hoon;Ahn, Hae-Seong
    • Journal of the Society of Naval Architects of Korea
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    • v.42 no.3
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    • pp.233-240
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    • 2005
  • A model test was carried out, in order to verify the hydrodynamic performances of public 30 feet class sailing yacht. In the initial design stage, the performances and the running attitude of sail yacht including the hull form and sail plan, appendages were estimated by VPP, from which made the representative test conditions. A new experiment system such as captive model device was composed because the running attitude could be changed by wind conditions. The test results show that the minimum resistance is generated in the heeling 20 degree, which was expected in the initial design stage. It is thought to be the useful informations that the keel has au effects on hydrodynamic forces and resistance differences between the upwind and the downwind condition.

A Study on the Motion Responses and the Drift Forces of Semi-Submersible Drilling Rigs in the Damaged Condition (손상 상태에서의 반잠수식 해양구조물의 운동 응답 및 표류력에 관한 연구)

  • Park, Rho-Sik;Kim, Seong-Keun;Kim, Jong-Hyeon
    • Journal of Ocean Engineering and Technology
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    • v.2 no.2
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    • pp.27-36
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    • 1988
  • For the purposes of drilling oil field and extracting oil deep water in more rough weather, the size of drilling rigs must be estimated. In this paper, the three dimensional source distribution method is used and we assume 10 deg. heeling and trimming condition of the drilling rig(SR-192). Also, the effects of the hydrodynamic forces which include the drift forces for field method, and the motion responses are studied with changing the incident wave direction in the assumed inclining condition. The theory and numerical codes used in this thesis appeared to be very useful for the preliminary design of drilling rigs.

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A Study on the Ship Resistance and Moment Prediction for Running Attitude of 30 Feet Catamaran Sailing Yacht (30ft급 쌍동형 세일링 요트의 항주자세에 따른 실선저항 및 모멘트 추정에 대한 연구)

  • Park, Chung-Hwan;Jang, Ho-Yun;Jeong, Jin-Wook;Lee, Byung-Sung;Chun, Ho-Hwan
    • Journal of the Society of Naval Architects of Korea
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    • v.47 no.3
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    • pp.321-327
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    • 2010
  • During sailing by wind-driven thrust on the sail, a catamaran sailing yacht generates leeway and heeling. For estimating resistance and moment prediction of a real ship by changing of running attitude, a model test of the ship has to be carried out. This study aims at establishing experimental techniques for a catamaran sailing yacht by changed attitude during running direction. Through the model test, drag and side force of the real ship are predicted. Also through experiment, rolling and yawing moments were considered.