• Title/Summary/Keyword: 선저경사각

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18.5ft급 배스보트의 선저경사각에 따른 성능 평가

  • Im, Jun-Taek;Seo, Gwang-Cheol;Lee, Gyeong-U;Gwak, Jin
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2018.11a
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    • pp.220-221
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    • 2018
  • 배스보트는 주로 민물에서 낚시를 위해 설계되는 소형 고속 활주형 선박으로 국내에서도 수요가 높은 편이다. 하지만 경기에 참가하는 선수들이 선호하는 17ft급 이상의 배스보트에 대해서는 수입에 100% 의존하는 중이다. 본 연구에서는 18.5ft급 배스보트의 주요요목 결정 및 선형을 개발하고, 선저경사각을 결정하기 위해 상용 CFD코드인 STAR-CCM+ v10.04를 사용하여 수치해석을 수행하여 각 선저경사각별 항주자세 및 저항성능을 분석하여 최적의 선저경사각을 갖는 선형을 도출하였다.

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Numerical Experimentations on Flow Impact Phenomena for 2-D Wedge Entry Problem (2차원 쐐기형 구조물 입수 시 발생하는 유체 충격 현상에 대한 수치 실험적 연구)

  • Yum, Duek-Joon;Du, Hun;Kim, Young-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.8
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    • pp.3374-3383
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    • 2011
  • In this study, numerical analyses for slamming impact phenomena have been carried out using a 2-dimensional wedge shaped structure having finite deadrise angles. Fluid is assumed incompressible and entry speed of the structure is kept constant. Geo-reconstruct(or PLIC-VOF) scheme is used for the tracking of the deforming free surface. Numerical analyses are carried out for the deadrise angles of $10^{\circ}$, $20^{\circ}$ and $30^{\circ}$. For each deadrise angle, variations are made for the grid size on the wedge bottom and for the entry speed. The magnitude and the location of impact pressure and the total drag force, which is the summation of pressure distributed at the bottom of the structure, are analyzed. Results of the analyses are compared with the results of the Dobrovol'skaya similarity solutions, the asymptotic solution based on the Wagner method and the solution of Boundary Element Method(BEM).

A Numerical Study on the Selection of Main Specification of the 18.5ft Bass Fishing Boat (18.5ft급 경기용 배스보트의 주요제원 선정에 관한 수치해석 연구)

  • Lim, Jun-Taek;Seo, Kwang-Cheol;Park, Geun-Hong;Kim, Sang-Won
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.7
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    • pp.945-952
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    • 2018
  • Recently, bass fishing has become a marine leisure sport in Korea. There are 4 major fishing associations in Korea, and each association holds 10-15 tournaments each year. However, supply of 17 ft bass boats, which are preferred in leagues, depends 100 % on imports. In this study, we have derived the main specifications to develop the initial hull forms of a 18.5ft bass boat through statistical analysis based on mothership data. In addition, CFD numerical analysis was carried out according to deadrise angle and longitudinal center of gravity, which strongly influenced the resistance and planing performance. For numerical analysis, design speed was set to $Fn=3.284 (Re=9.858{\times}10^7)$, the deadrise angle was set from 12 to $20^{\circ}$, and the longitudinal center of gravity was set in the range of 0 to $8%L_{wL}$ from the center of buoyancy to the stern. Based on the numerical results, we first set the range of these factors by resistance performance and immersion keel length. Furthermore, using a correlation graph of Savitsky's Drag-Lift ratio, we derived the deadrise angle ($14-16^{\circ}$) and longitudinal center of gravity ($4-6%L_{wL}$).

Study of Hull Form Development of Wave-Piercing-Type High-Speed Planing Boat (파랑관통형 고속활주선 선형개발에 관한 연구)

  • Jeong, Uh-Cheul;Lee, Dong-Kun;Jung, Ki-Seok
    • Journal of Ocean Engineering and Technology
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    • v.30 no.2
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    • pp.69-74
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    • 2016
  • A new wave-piercing-type high-speed planing boat without a chine was developed, and its basic performance was investigated in a model test, including the resistance, trim, and sinkage. The maximum speed of the developed ship was 35 knots. The hull form was developed by combining a VSV (very slender vessel) and TH (transonic hull), which have large deadrise angles at the bow. The main dimensions were estimated by a statistical approach using actual ship data. The effect of a side fin attached at the stern near the water line was investigated from a resistance point of view. It was found that the developed hull form showed the possibility of a new concept for a high-speed planing hull without a chine, and the side fin played an important role in increasing the resistance performance by controlling the trim and sinkage in the high-speed range.

A Study on the Resistance Characteristics of Leisure Boat According to Chine Shape (차인 형상에 따른 레저선박의 저항특성에 관한 연구)

  • Kim, Juyeol;Choi, Junho;Oh, Jungkeun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.5
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    • pp.566-573
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    • 2017
  • The chine of high speed vessels does not only play a role in changing position when planing but also helps balancing the hull. It also has a great influence on resistance performance. However, designing a chine requires a lot of experience because it is influenced by various factors such as displacement, transom shape, draft and width. Such a design is not based on an empirical formula, but the purpose of this study is to provide basic guidelines regarding the shape of chine through calculation. This design was developed using Yacht-one, a commercial design program, and analysis was performed using Star-CCM+, also a commercial analysis program. Analysis of the hull selected in this study was carried out by Dynamic Fluid Body Interaction (DFBI) method. Analysis of the chine was carried out at chine angles of 15, 16, 17, and 19degrees, at a speed of 30knots. The result indicated that the highest trim occurred at 16 degrees among the four chine angles considered, and the highest heave occurred at 15degree. In terms of resistance performance, minimum resistance was observed at 16 degrees. Consequently, for minimum ship resistance, it is necessary to complete calculations in accordance with the chine angles, ${\pm}2$ degrees from the initial chine angle, which should be carried out a the design stage.