• Title/Summary/Keyword: Twin rudder

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A Study on the Prediction of Maneuvering Motion for a Twin-Screw Twin-Rudder Ship at Initial Design Stage (초기설계 단계에서 2축2타선의 조종운동 추정에 관한 연구)

  • 이승건;이경우;이승재
    • Journal of the Korean Institute of Navigation
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    • v.21 no.1
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    • pp.103-108
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    • 1997
  • Mathematical model of maneuvering motion for a single-screw single-rudder ship is established and several applications to the special situations of maneuvering are attempted. While, the mathematical model for twin-screw twin-rudder ship is not presented so much, because that type of ship is not popular. Lee et al. have examined the characteristics of such ship by captive model tests in 1988, in Japan. This paper proposes new mathematical models for propeller effective wake (1 -${\omega}_p$) and effective neutral rudder angle ${delta}_R$ in the case of twin-screw twin-rudder ship. And some maneuvering motionse are calculated with proposed models and compared with exact simulations.

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A Study on the Prediction of Maneuvering Motion for a Twin-Screw Twin-Rudder Ship at Initial Design Stage (초기설계 단계에서 2축2타선의 조종운동 계산에 관한 연구)

  • 이승건;이경우;이승재
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1996.09a
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    • pp.81-88
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    • 1996
  • Mathematical model of maneuvering motion for a single-screw single-rudder ship is established and several applications to the special situations of maneuvering are attempted. While the mathematical model for twin-screw twin-rudder ship is not studied presented so much because that type of ship is not popular. Lee et al. have examined the characteristics of such ship by captive model tests in 1988 in Japan. This paper proposes new mathematical models for propeller effective wake (1-wp) and effective neutral rudder angle $\delta$R in the case of twin-screw twin-rudder ship. And some maneuvering motions are calculated with proposed models and compared with exact simulations.

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Control effects of the hydrodynamic force of twin rudder in a uniform stream (균일 흐름중에 놓인 쌍동타의 간격변화가 유체력 제어효과에 미치는 영향)

  • Shon, Chang-Bae;Oh, Woo-Jun;Ku, Youn-Kyoung;Gim, Ok-Sok;Lee, Gyoung-Woo
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2010.04a
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    • pp.387-388
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    • 2010
  • An open water rudder test was carried out to figure out the flow characteristics around a twin rudder at $Re=1.5\times10^4$. In the analysis, the unique characteristics of a twin rudder, which effects rudder farces, were explained. The analysis is included varying angles of attack fram 10 to 30 degree. In this paper, the measured results has been compared with each other to predict the performance characteristics of a twin rudder's 2-dimensional section by 2-frame grey level cross correlation PIV method. The side force of the rudder could be mainly improved at 0.75L.

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Trajectory Optimization for Autonomous Berthing of a Twin-Propeller Twin-Rudder Ship

  • Changyu Lee;Jinwhan Kim
    • Journal of Ocean Engineering and Technology
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    • v.37 no.3
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    • pp.122-128
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    • 2023
  • Autonomous berthing is a crucial technology for autonomous ships, requiring optimal trajectory planning to prevent collisions and minimize time and control efforts. This paper presents a two-phase, two-point boundary value problem (TPBVP) strategy for creating an optimal berthing trajectory for a twin-propeller, twin-rudder ship with autonomous berthing capabilities. The process is divided into two phases: the approach and the terminal. Tunnel thruster use is limited during the approach but fully employed during the terminal phase. This strategy permits concurrent optimization of the total trajectory duration, individual phase trajectories, and phase transition time. The efficacy of the proposed method is validated through two simulations. The first explores a scenario with phase transition, and the second generates a trajectory relying solely on the approach phase. The results affirm our algorithm's effectiveness in deciding transition necessity, identifying optimal transition timing, and optimizing the trajectory accordingly. The proposed two-phase TPBVP approach holds significant implications for advancements in autonomous ship navigation, enhancing safety and efficiency in berthing operations.

Research on the Prediction of Maneuvering Motion for a Twin-Screw Twin-Rudder Ship (2축(軸)2타선(舵船)의 조종운동 추정(推定)에 관한 연구)

  • Lee, Seung Keon;Kim, Yoon Su;Lee, Seung Jae
    • Journal of the Society of Naval Architects of Korea
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    • v.33 no.4
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    • pp.60-65
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    • 1996
  • Mathematical model of maneuvering motion for a single-screw single-rudder ship established and versatile applications to the special situations of maneuvering are attempted. While, the mathematical model for twin-screw twin-rudder ship is not presented so much, because that type of ship is not popular. Lee et al. have examined the characteristics of such ship by captive model tests in 1988. This paper treats new mathematical models for propeller effective wake ($1-w_p$) and effective neutral rudder angle ${\delta}_R$ in the case of twin-screw twin-rudder ship. And some maneuvering motions are calculated with proposed models and compared with exact simulations.

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Control Effects of the Hydrodynamic Force of the Submerged NACA0018 arranging in a Row in a Uniform Stream (균일흐름 중에 놓인 병렬구조를 가진 몰수형 NACA0018의 간격변화가 유체력 제어효과에 미치는 영향)

  • Gim, Ok-Sok;Shon, Chang-Bae;Lee, Gyoung-Woo
    • Journal of Navigation and Port Research
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    • v.34 no.5
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    • pp.325-330
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    • 2010
  • An open water rudder test was carried out to figure out the flow characteristics around a twin rudder at $Re=1.5{\times}10^4$. In the analysis, the unique characteristics of a twin rudder, which affects rudder forces, were explained. The analysis includes varying angles of attack from 10 to 30 degrees. In this paper, the measured results have been compared with each other to predict the performance characteristics of a twin rudder's 2-dimensional section by 2-frame grey level cross correlation PIV method. The length L=0.75C between upper and lower rudders could be defined as the critical length.

Study on the Maneuvering Characteristics of a Container Ship with Twin Skegs (쌍축 컨테이너선의 조종성능 특성 연구)

  • Kim, Yeon-Gyu;Kim, Sun-Young;Kim, Hyoung-Tae;Yu, Byeong-Seok;Lee, Suk-Won
    • Journal of the Society of Naval Architects of Korea
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    • v.43 no.1 s.145
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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.

A Study On Mathematical Model of Manoeuvring Motions of Twin-screw and Twin-rudder Ship for Construction of Real-time Ship-handling Simulator (시뮬레이터 구축을 위한 2축2타선박의 조종운동 수학모델에 관한 연구)

  • 손경호;김용민
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.7 no.3
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    • pp.1-16
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    • 2001
  • In view of the fact that marine casualties have more often occurred recently, there is a need for ship-handling simulator as a useful tool for maritime training, safety assessment and so on. Moreover various kinds of hull forms have appeared for the purpose of improving ship manoeuvrality. Therefore ship-handling simulator is in need of a database for various ships, and it can make diverse maneuvering simulations possible to apply respective mathematical model to ship-handling simulator. In this paper, we adopted twin-screw and twin-rudder ship and discussed mathematical model of maneuvering motions for her. It was discussed from the viewpoint of hull damping forces at low advance speed and interaction between hull, propeller and rudder. Using this model, maneuvering motion of twin-screw and twin-propeller ship was simulated numerically and her principal manoeuvrability was examined.

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A Numerical Study on the Maneuverability of a Twin-screw Ship under Single Rudder Failure (쌍축 추진 선박의 단독 타 고장 상태에서의 조종성능에 대한 수치적 연구)

  • You, Youngjun;Kim, Hyunjun
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.2
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    • pp.161-169
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    • 2017
  • Recently, ship owners have been requiring the assessment of the maneuverability of twin-screw ships under mechanical failures. Because this kind of assessment has not yet been conducted, it is necessary to study the types of machinery failures that can significantly affect the maneuverability of a ship, and to construct a procedure to simulate the maneuvering behavior under such failures. In this paper, the sole focus is the steering system failure from among the variety of failure types, and the maneuvering behavior of the ship under the single rudder failure is simulated for an investigation of the unique characteristics. First, the mathematical model for the twin-screw container ship is verified by comparing the simulated results for the $35^{\circ}$ turning test, $10^{\circ}/10^{\circ}$ zigzag test, and $20^{\circ}/20^{\circ}$ zigzag test under the normal operating condition with those obtained from free running model tests. After the IMO maneuvering tests are additionally simulated under the single rudder failure, the results are reviewed to investigate the maneuvering characteristics that are due to the failure. Further, the $35^{\circ}/35^{\circ}$ zigzag test and the $35^{\circ}$ turning test are simulated to additionally investigate the effects of the single rudder failure on the steering and turning abilities.

Experimental Study of the Flat & Twisted Rudder Characteristics Using Rudder Dynamometer in LCT (LCT에서 방향타 동력계를 이용한 평판 및 비틀림 방향타 특성의 실험적 연구)

  • Ahn, Jong-Woo;Paik, Bu-Geun;Park, Young-Ha;Seol, Han-Shin
    • Journal of the Society of Naval Architects of Korea
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    • v.58 no.6
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    • pp.391-399
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    • 2021
  • In order to investigate force and cavitation characteristics for the flat & twisted rudders in the Large Cavitation Tunnel (LCT), the rudder dynamometer was designed and manufactured. The measuring capacities of lift, drag and moment are ±1000 N, ±2000 N, and ±150 N-m, respectively. The present dynamometer uses the actuator with a harmonic drive to control the rudder angle without backlash. As the target ship is a military ship with twin shaft, each dynamometer was installed above the port & starboard rudders. After the installation of the model ship with all appendages, the model test composed of rudder force measurement and cavitation observation was conducted for the existing flat rudder & the designed twisted rudder. While the flat rudder showed the big difference of lift & moment between port & starboard, the twisted rudder presented a similar trend. The cavitation of the twisted rudder showed better characteristics than that of the flat rudder. Another set of model tests were conducted to investigate rudder performance by the change of the design propeller. There was little difference in rudder performance for the design propellers with slight geometric change. Through the model test, the characteristics of the flat & twisted rudders were grasped. On the basis of the present study, it is thought that the rudder with better performance would be developed.