• 대한조선학회 특별논문집
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• 대한조선학회 2007년도 특별논문집
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• pp.74-78
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• 2007

In this paper, the HPMM(Horizontal Planar Motion Mechanism) test is simulated in a numerical towing tank by using a commercial CFD(Computational Fluid Dynamics) code, FLUENT. The results of calculation are compared with those of static drift test or rotating arm test calculated by CFD to verify the results simulated by CFD. Through comparing pure sway test of HPMM test with static drift test and pure yaw test of HPMM with rotating arm test, it is found that HPMM test can be simulated in the numerical towing tank.

• 대한조선학회논문집
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• 제43권2호
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• pp.164-170
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• 2006

To improve ship's maneuverability and carry out special goal POD propulsion system was equipped as propulsion and maneuvering system. To predict the maneuverability of a ship with POD propulsion system HPMM tests and POD open water test are carried out. In this paper modular model with 4 degree of freedom of a ship with twin POD propulsion system is presented. To use modular model the forces of POD propulsion system are measured separately from the hull forces. The measured forces and moments are analyzed by using modular model and whole ship model The simulation results of modular model are compared with those of whole ship model. From the present study it is Possible to analyze HPMM tests of a ship with twin POD propulsion system by modular model.

• 대한조선학회논문집
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• 제43권2호
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• pp.171-176
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• 2006

To improve ship's maneuverability high lift rudders like as Schilling rudder, flap rudder etc. were used. To predict the maneuverability of a ship with flap rudder HPMM tests are carried out. To analyze the test results modular model is used. To use modular model the forces of flap rudder must be measured separately from the hull forces. The flap rudder is made as independent system from the hull. To investigate the simulation results of modular model the tests results are analyzed by whole ship model, and simulated. The compared results of simulation show a good agreement except turning test. The reason is the different analysis result of flap rudder drag forces. From the present study it is possible to analyze HPMM tests of a ship with flap rudder by modular model.

• 대한조선학회논문집
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• 제43권1호
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• pp.15-21
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• 2006

Recently, the attention to large container ships whose size is greater than 10,000 TEU container ship has been increased due to their increasing demand. The large container ship has twin skegs because of the engine capacity and large beam-draft ratio. In this paper, the maneuvering characteristics of a container ship with twin skegs were investigated through 4DOF(four degree of freedom) HPMM(Horizontal Planar Motion Mechanism) test and computer simulation. A mathematical model for maneuvering motion with 4DOF of twin skegs system was established to include effects of roll motion on the maneuvering motion. And to obtain roll-coupling hydrodynamic coefficients of a container ship, 4DOF HPMM system of MOERI which has a roll moment measurement system was used. HPMM tests were carried out for a 12,000 TEU class container ship with twin skegs at scantling load condition. Using the hydrodynamic coefficients obtained, simulations were made to predict the maneuvering motion. Rudder forces of twin-rudders were measured at the angles of drift and rudder. The neutral rudder angles with drift angles of ship was quite different with those of single skeg ship. So other treatment of flow straightening coefficient $\gamma_R$ was used and the simulation results was compared with general simulation result. The treatment of experimental result at static drift and rudder test was very important to predict the maneuverability of a container ship with twin skegs.

• 대한조선학회논문집
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• 제41권5호
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• pp.28-33
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• 2004

Generally Horn-type rudders have been used for single propeller and single rudder system. The reason is that the rudder torques of Horn-type rudder are smaller than those of Spade rudder with same lift force. But it is found that the rudder cavitation occurs on a Horn-type rudder of fast container ship. In this paper the comparison results of Horn-type and Spade rudders are described. HPMM tests are carried out to compare the effects of two rudder types on the maneuverability of a ship. It is shown that the maneuvering performance of a ship equipped with Horn-type rudder is better than that equipped with Spade rudder by comparing the test results and maneuvering coefficients at scantling condition. The reason is that the movable part area of Horn-type rudder is about 14％ larger than that of Spade rudder with same total area. And the rudder torque of Spade rudder is greater than that of Horn rudder. At ballast condition, however, the effect of rudder type is negligible.

• 대한조선학회논문집
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• 제51권6호
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• pp.539-547
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• 2014

Ship squat is a well known phenomenon, which means an additional sinkage and a change of trim when a ship sails in shallow water. As a series of ship squat study, a HPMM(Horizontal Planar Motion Mechanism) test of KVLCC2 model ship to measure a sinkage and a trim in shallow water was conducted. Additionally a CFD(Computational Fluid Dynamics) analysis was carried out to simulate fluid flows around the ship surface. A change in ship speed, drift angle at three depth conditions(H/T = 1.2, 1.5 & 2.0) is considered for comparing these results. As a result, an increase of the ship speed and the drift angle caused an increase in ship squat in EFD(Experimental Fluid Dynamics), and created a lower pressure on the ship bottom area in CFD. Lastly the sinkage results of KVLCC2 by EFD and CFD are compared to results by three empirical formulas. The tendency of sinkage by EFD and CFD is similar to the results of empirical formulas.

• 대한조선학회논문집
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• 제51권1호
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• pp.34-41
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• 2014

When a ship sails in shallow water, it is well known that an additional sinkage and trim of the ship(squat) is caused by change of hydrodynamic force between the seabed and the bottom of a ship. In this paper, to examine this phenomenon by model tests, the squat of KCS model ship at a low speed is measured by the vision based ship motion measurement system during HPMM tests. Various combinations of a ship speed, a rudder angle and a drift angle were tested at three depth conditions(H/T = 1.2, 1.5 & 2.0). As a result, increase of the ship's speed and ship's drift angle caused an increase in ship squat, but the ship's rudder angle did not. The rate of increase in ship squat was the most at H/T = 1.2 condition. Lastly these experimental results are compared to the results by three empirical formulas and two CFD methods. The tendency of ship squat measured by experiment is similar to those of empirical formulas.

• 한국항해항만학회지
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• 제36권8호
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• pp.613-618
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• 2012

부선이 선미 예인되는 상황에서의 예부선 통합시뮬레이션을 수행하기 위하여, 본 연구에서는 부선 단독 조종성능 추정을 위한 구속모형실험을 수행하였다. 구속모형실험결과로부터 부선 실선의 저항성능을 추정하였고, 도출된 유체력 미계수를 이용하여 선회시뮬레이션을 수행하였다. 부선의 선회시뮬레이션을 위해 부선에 작용하는 예인력의 힘과 방향을 단순히 모델링하고, 예인줄 방향각 변화에 따른 선회시뮬레이션 결과 비교와 실선시운전시험결과와의 선회직경 비교를 통하여 수학모델을 검증하였다. 그 결과 예인줄 방향각이 커질수록 선회직경이 작아지는 정성적인 경향을 확인하였고, 실선시운전결과와 비교 시 배수량 차이 등에 의하여 선회직경이 작게 추정되는 결과를 확인하였다.

• 대한조선학회논문집
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• 제34권2호
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• pp.48-55
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• 1997

본 논문은 초기설계 단계에서 HPMM시험을 이용하여 조종성능을 추정하기 위해서 Abkowitz와 MMG 수학모델을 비교하였다. 본 논문에서 MMG 해석에 의한 알고리즘은 일본의 MMG 그룹의 해석 방법을 적용하여 연구되었다. 해석 결과는 정유운반선을 대상선박으로 선정하여 Abkowitz 수학모형 및 실선 시운전 결과와 비교 되었다.

• Journal of Ship and Ocean Technology
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• 제6권2호
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• pp.23-36
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• 2002

This paper describes the powering, seakeeping and maneuvering performances for a 2,500-ton class trimaran. Influence of the side-hull forms and location of those in longitudinal and transverse direction to resistance performance was systematically investigated by a series of model tests and numerical calculations. It was found that the longitudinal location of side-hulls was the most influential design parameter to the resistance performance of the trimaran and the optimum location of side-hull depends on ship speeds. When the side-hull stem is located near the primary wave hollow generated by the main hull, the trimaran shows the best resistance performance. Powering performance of the trimaran is superior to those of similar mono-hull ships. Seakeeping model tests for the trimaran were executed and the results were compared with the theoretical results of a similar mono-hull ship. Generally speaking, seakeeping performance of the trimaran is superior to that of a mono-hull ship. In particular, pitching and rolling performance of the trimaran is excellent, which is due to the increased length and breadth. Maneuvering model tests using a HPMM equipment were executed to evaluate the maneuvering performance of the trimaran. Maneuvering simulation was performed using the maneuvering coefficients from the model tests. The results show that the control ability of heading angle and the direction keeping stability of the trimaran is excellent, even though the turning performance is rather worse compared to those of a similar mono-hull ship.