• 대한조선학회논문집
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• 제40권1호
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• pp.1-7
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• 2003

The effect of the passive anti-rolling tanks(ART) decreases when the roll period of the vessel does not match the designed oscillating period of the fluid in the tank. In order to improve the effect of the passive ART, the damping plates are installed in the lower duct of the ART to adjust the oscillating period of the fluid. The effects of the damping plates on the oscillating period of the fluid and the changes of the stabilizing moments are examined through the series of bench tests. Acryl model tank larger than 1m breadth is made to minimize the viscous effect of the tank and the stabilizing moments of the tank are measured for various roll angles. Using the obtained tank damping coefficient, RAO(Response Amplitude Operator) value in the resonance range is computed and the stabilizing effect of a ART has been estimated.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2006년도 추계학술발표회
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• pp.265-269
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• 2006

파랑에 의한 선박의 횡동요를 방지하는 감요장치는 크게 수동식과 능동식 으로 분류할 수 있으며 수동형 감요수조는 선박에서 가장 널리 사용되고 있다. 이 연구에서는 감요장치의 하부덕트유동에 관한 기초연구로서 덕트의 제어 댐퍼와 유입부의 유통에 대해 입자영상 유속측정장치를 이용하여 속도벡터분포에 관한 정량적인 데이터를 확보하였다. 그 결과 실험관 벽면에서 측정 된 압력의 분포는 디스크가 전개 상태인 0 도에서 45도까지는 입구 압력은 일정한 상태로 거의 변화하지 않았으나 약 60도 이상에서부터 압력 상승과 점차 급격한 변동현상이 나타났다.

• 대한조선학회논문집
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• 제52권2호
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• pp.135-142
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• 2015

The Anti-Rolling Tank(ART) has an advantage over the other roll stabilizing devices, when ship is staying and working at one site of sea. An important design point of ART is the tank tuning, that is, matching the tank natural period to the ship's roll natural period. Since the load condition and consequently the roll natural period of ship is to be changed widely, the natural period of ART also has to be changed widely. In case of the existing U-tube type ART with a single layer duct, the tank natural period can be changed in a relatively narrow range. This paper suggests a new U-tube type ART system using a double layer duct to enable wide change of ART natural period. Through the roll experiments performed in regular beam waves for a box-type model ship, it is shown that the double layer duct ART has about two times wider period range and a better reducing effect of roll magnitude than the single layer duct ART.

• 대한조선학회논문집
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• 제52권6호
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• pp.452-459
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• 2015

It is important to use bench test results in the design process of anti-rolling tanks. Traditional bench tester is usually designed to perform only roll motions about a fixed axis and relatively small so that the viscous effects may not be neglected. Novel bench tester which could adjust the motion center to realize the coupled motion of sway and roll has been devised and manufactured therefore, large scaled bench tester could be utilized for designing the passive anti-rolling tanks. The time history of the reference signal from the rotation sensor of the bench tester have been recorded and processed to determine the phase angle to derive the Response Amplitude Operator(RAO) of the stabilized ship. The breadth of ART tank model should be large up to 2 m to diminish viscous scale effect and the vertical position of the tank can be varied with the ship's center of motion. The periods and the amplitude of roll motion can be varied from 1.5 sec to 5 sec and up to ±20°, respectively. The components of the tester was expressed in three dimensional digital mockup (DMU) and assembled together in the CAD space. The final configuration of the bench tester has been determined by confirming the smooth operation of the moving parts without interference through the animation in CAD space. New analytic logic are introduced for the determination of hydrodynamic moment and phase difference due to fluid motion in ART and verified through the test. The developed bench tester is believed to be effective and accurate for the verification of stabilization effect of ART taking into the consideration of the sway effect in the design stage.

• 대한조선학회지
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• 제11권1호
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• pp.17-26
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• 1974

In this paper, authors investigate and analyze the effects of the anti-rolling tank which are calculated in accord with the tank damping coefficients by the computer, and which are represented with both the tank water's saturating state and the normal state in the irregular waves by analog computer. As the results of these studies, we immediately find that the tank optimum damping coefficient $b_{to}$, is 0.3877 due to calculating $\mu$-values, analyzing and comparing inclinations of $\mu$-values, and that although a nonlinear elements are included in the response character of the ship-tank system, the output is no longer Gaussian distribution, even when the sea waves are considered as Gaussian, and can not be expressed by the spectral forms which premise the superposition theory.

• 대한조선학회지
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• 제8권2호
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• pp.35-44
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• 1971

In terms of this paper, concerning primarily with the U-tube tank stabilizer, the authors' aim is to clarify and consolidate the theory as it has been developed thus far, and to provide with the certain additions which will make it more complete, more accurate, and more practical. And then we can know that the effect of the vertical tank position from the C.G., $a_{st}=1-w^2/{w^2}_{st}$, is very important, on account for the fact that the position factor, $a_{st}$, increase when the anti-rolling tank attaches to higher position vertically, but $a_{st}$ does not increase in proportion to the distance of the tank position. Measuring many characteristic coefficients by experiment, in the equation of the ship-tank system motion, such as the inertia coefficient, the damping coefficient, the natural frequency and so on, they can also give a guess that the higher position will accompany the non-linear motion of the tank water, but the non-linear effect will decrease the tank ability. In this study, they deal with not only the optimum damping coefficient of tank, which has very simply been expressed by the strength ratio, $\lambda$, but also the effect of the tank top, which has experimentally been treated when the water has hit the tank top. As this result, we can immediately find that the ability of the anti-rolling tank decrease at w/ws=0.9 generally low frequency.

• 수산해양기술연구
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• 제40권2호
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• pp.138-143
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• 2004

제주대학교 실습선 아라호에 정착된 능동형 횡동요 감쇠장치의 성능에 관해 연구하기 위하여 33$^{\circ}$00‘.44”N, 125$^{\circ}$59’.88 ”E 위치에서 선박을 정지한 후, 횡동요 감쇠장치를 정지 (Passive A.R.T), 작동 (Active A.R.T)을 했을 때 경사계에 의한 횡동요각 및 종동요각, 풍속계에 의한 풍속의 변화와 그리고 선박이 항해 중에 감쇠장치의 작동을 정지(Passive A.R.T), 작동(Active A.R.T) 했을 때 의 능동형 횡동요 감쇠장치의 성능을 분석한 결과에 대해 요약하면 다음과 같다. 1. 선박이 정지했을 때 횡동요 감쇠장치를 정지, 작동한 경우 횡동요각의 평균진폭 (Average Amplitude of Roll) 은 각각 8.30$^{\circ}$, 4.37$^{\circ}$, 횡동요각의 유의진폭(Significant Amplitude of Roll $_{{\pi}{1/3}}$)은 각각 10.10$^{\circ}$, 5.30$^{\circ}$으로 나타났다. 2. 선박이 항해 중 일 때에는 횡동요각의 평균진폭 (Average Amplitude of Roll)은 각각 5.01$^{\circ}$, 4.36$^{\circ}$, 횡동요각의 유의진폭 (Significant Amplitude of Roll$^{\circ}$) 은 각각 5.50$^{\circ}$, 5.10$^{\circ}$으로 각각 나타났다. 3. 횡동요 감쇠장치는 선박이 정치했을 때에는 47.5%, 선박이 운항 했을 때는 12.7% 정도의 감쇠 효율을 보여서 정지했을 때 그 효율이 높은 것으로 나타났다. 4. 횡동요 감쇠 장치는 종동요(Pitching)에 대해서는 거의 영향을 미치지 않았다.