• 대한조선학회논문집
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• 제56권6호
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• pp.550-558
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• 2019

The roll motion of a general vessel, which is more influenced by resonance as compared to other motions, adversely affects the passenger and hull. Therefore, reducing the roll motion through an anti-rolling system is critical, and most ships use various devices such as anti-rolling tanks, bilge keels, and fin stabilizers to accomplish this. In this study, a simplified model is developed for the application of an anti-rolling device for unmanned semi-submersible vessels. The applied anti-rolling device is installed on the stern and stem of a ship using a pair of servo motors with added weight, and the motor is controlled through the Arduino. The moment of the motor is designed and implemented based on a mathematical model such that it is calculated through the restoring force according to the heel angle of the ship. The performance of the proposed system was verified by utilizing the roll damping coefficient calculated by the free-roll decay test and logarithmic decrement method and was validated by a towing tank test. The system is expected to be used for unmanned vessels to perform sustainable missions.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.725-731
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• 2003

Reduction of a ship's rolling is the most important performance requirement for improving the safety of the crew on board and preventing damage to cargos as well as improving the comfort of the ride. A mass driving anti-.oiling system (MD-ARS) might be one candidate of several systems against the ship's rolling. As the movable range of the mass on the ship is finite, the control system must include restriction on the mass position to protect the device and the ship. This restriction usually causes windup phenomenon and control performance is deteriorated seriously. We adopt anti-windup technique to improve the control performance and demonstrate its efficiency by simulation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.727-730
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• 2004

Reduction of a ship's rolling is the most important performance requirement for improving the safety of the crew on board and preventing damage to cargos as well as improving the comfort of the ride. A mass driving anti-rolling system (MD-ARS) might be one candidate of several systems against the ship's rolling. In this paper, three types of MD-ARS, two passive and one active devices, are developed for small ships. After they are installed on the cabin of the small leisure boat, respectively, a series of test is conducted before and after operating them. Through the test, it is confirmed that the roll responses of the ship are pretty well reduced by the system.

• 한국항해항만학회지
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• 제41권6호
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• pp.365-372
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• 2017

부유체의 횡동요는 승조원의 피로를 누적시키고, 심지어 구조물 전체를 전복시키기까지 하고, 또 선체에 반복적인 외력을 가하는 등 부유체의 안정성과 구조물의 안전에 심대한 영향을 끼친다. 그래서 거의 모든 선박의 경우에는 빌지킬을 설치하여 횡동요를 감소시키고 있고, 특수한 경우에는 안티롤링 탱크나 핀 스태빌라이저나 자이로스코프 등을 설치하여 횡동요를 줄이고 있다. 그러나 안티롤링 탱크는 설치하는데 용적을 많이 차지하고, 핀 스태빌라이저나 자이로스코프는 설치비와 유지 관리비가 많이 든다. 저자들은 안티롤링진자를 이용한 부유체의 롤링저감에 대한 연구를 하여 실험과 Runge-Kutta 해석에 의하여 그 유효성을 보인 바 있다. 여기에서는 선박에 안티 롤링 진자를 설치한 모델을 2자유도 점성감쇠계로 선형화하여 시스템을 해석하고 실험과 비교하여 수학 모델의 정당성을 보이고, 수학 모델의 정당성을 바탕으로 최적의 안티 롤링 진자를 제안한다. 7.7kg의 모형선의 경우 모형선 질량의 0.26%인 20g의 안티롤링 진자가 가장 효율이 좋음을 보였다. 또 안티 롤링 진자의 질량이 다른 몇 가지 경우에 대하여서 자유 롤링 실험을 하여 안티 롤링 진자의 유효성을 보인다.

• 한국항해항만학회지
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• 제34권4호
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• pp.271-279
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• 2010

The Mobile Harbor(MH) is a new transportation platform that can load and unload containers to and from very large container ships in the sea. This loading and unloading by crane can be performed with only very small movements of the MH in waves because MH is operated outside of the harbor. For this reason, an anti-rolling tank(ART) and an active mass driving system(AMD) were designed to reduce MH's roll motion, especially at the natural frequency of MH. In the conceptual design stage, it is difficult to confirm the design result of theses anti-rolling devices without modeling and simulation tools. Therefore, the coupled MH and anti-rolling devices' dynamic equations in waves were derived and a simulation program that can analyze the roll reduction performance in various conditions, such as sea state, wave direction, and so on, was developed. The coupled equations are constructed as an eight degrees of freedom (DOF) motion that consists of MH's six DOF dynamics and the ART's and AMD's control variables. In order to conveniently include the ART's and AMD's control dynamics in the time domain, MH's radiated wave force was described by an impulse response function derived by the damping coefficient obtained in the frequency domain, and wave exciting forces such as Froude-Krylov force and diffraction force and nonlinear buoyancy were calculated at every simulation time interval. Finally, the roll reduction performances of the designed anti-rolling devices were successfully assessed in the various loading and wave conditions by using a developed simulation program.

• 대한조선학회논문집
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• 제42권6호
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• pp.666-672
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• 2005

Reduction of a ship's rolling is the most important performance requirement for improving the safety of the crew on board and preventing damage to cargos as well as improving the comfort of the ride. A mass driving anti-rolling system (MO-ARS) might be one candidate of several systems against the ship's rolling. In this paper, three types of MD-ARS, two passive and one active devices, are developed for small ships. After they are installed on the cabin of the small leisure boat, respectively, a series of performance test is conducted before and after operating them. Through the test, it is confirmed that the roll responses of the ship are pretty well reduced by the MO-ARS.

• 해양환경안전학회지
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• 제11권1호
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• pp.23-28
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• 2005

선박 횡동요는 물적 손실을 초래할 뿐만 아니라, 승선자의 거주성, 안전성 및 작업능률을 저하시키는 가장 큰 요인이 된다. 횡동요억제를 위한 많은 연구는 다양한 형태의 장치개발이라는 결과를 가져왔으며 상당한 효과를 얻고 있다. 지금까지 개발 된 대부분의 장치는 그 성능을 고려하지 야더라도 특수한 목적의 선박을 대상으로 설치$\cdot$운영되고 있으며, 고가이고 복잡하여 설치 상에도 많은 문제점을 안고 있다. 따라서 본 논문에서는 선박의 선미측에 설치한 플랩을 이용하여 운항중인 선박의 횡동요 억제에 관해 고찰하고 있다. 본 장치는 중$\cdot$소형의 선박에도 쉽게 설치하여 운용이 용이할 뿐만 아니라, 적절한 제어시스템 구축으로 피칭운동도 제어할 수 있는 장점이 있다. 본 논문에서는 이러한 장치를 설치한 선박에 대해 실험적 기법을 이용하여 모델링을 행하고 시뮬레이션을 통해 장치의 횡동요 억제효과를 검증하고 있다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.833-847
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• 2021

The horizontal porous baffle and its effect as an anti-slosh device have been investigated intensively in a swaying and rolling rectangular tank. To accurately assess the level at which porous baffles reduce liquid sloshing, the Matched Eigenfunction Expansion Method (MEEM) has been utilized as an analytical tool. The velocity potentials in the horizontal baffle-covered fluid region are expressed by the sum of the homogeneous and particular solutions to avoid solving the complex dispersion equation. By applying an equivalent linearized quadratic loss model, the nonlinear algebraic equation is derived and solved by implementing the Newton-Raphson iterative scheme. To prove the validity of the present theoretical model, a series of experiments have been conducted with different centered horizontal porous baffles with varying porosities and submerged depths in a swaying and rolling rectangular tank. Reasonably good agreements are obtained regarding the analytical solutions and the experiment's findings. The influence of porosity, submerged depth, and length of a centered horizontal porous baffle on anti-slosh performance have been analyzed, especially at resonance modes. The developed predictive tool can potentially provide guidelines for optimal design of the horizontal porous baffle.

• 한국해양공학회지
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• 제32권6호
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• pp.440-446
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• 2018

The effects of an anti-rolling tank (ART) on vessel motions were numerically investigated. The potential-based BEM vessel motion simulation program and particle-based computational fluid dynamics program were dynamically coupled and used to perform a simulation of vessel motions with ART. From the time domain simulation results, the response amplitude operators for sway and roll motions were obtained and compared with the corresponding experimental and numerical results. Because the main purpose of ART was only to reduce roll motions, it was important to show that the natural properties of a floating vessel were not changed by the effects of ART. Various ART filling ratios and several ART positions were considered. In conclusion, ART only reduced the roll motion regardless of its filling ratio and position.

• 공업화학
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• 제34권1호
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• pp.69-74
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• 2023

화학적 제빙 방법으로 프로필렌글리콜 제빙액은 동절기 고속철도차량 하부 및 대차부에 부착되는 설빙으로 인한 결빙을 녹이는데 적용가능하다. 프로필렌글리콜 제빙액을 운행 전 고속철도차량에 철도차량 하부 및 대차부에 미리 살포하여 눈의 부착을 최소화하면 해빙 효율을 더 높일 수 있다. 고속철도의 경우 프로필렌글리콜 제빙액을 살포하여도 고속으로 운행 시 대차 표면에서 제빙액은 거의 소실되기 때문에 눈의 부착으로 인한 결빙에 대한 방빙성능은 떨어진다. 본 연구에서는 동절기 고속철도차량 하부 및 대차부에 부착되는 설빙으로 인한 결빙을 방지하기 위해 표면의 결빙을 방지하는 발수 성분을 포함하는 프로필렌글리콜 제·방빙액의 특성을 연구하였다. 발수제의 종류에 따른 점도, 융빙성능, 접촉각 및 방빙성능에 대한 비교 평가를 실시하여 고속철도차량 제·방빙액으로 최적의 물질을 찾고자 하였다. 평가 결과 에톡시실란 타입의 발수제 성분을 포함하는 제·방빙액이 가장 적합한 것으로 확인하였다.