• 한국항해학회지
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• 제13권2호
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• pp.57-73
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• 1989

This paper presents a practical method to predict the characteristics of ship manoeuvring motions. A attempt is made to calculate the manoeuvring motions utilizing principal particulars of ship hull, properller and rudder as basic input data. The mathematical models, which describe the ship manoeuvring motions, are developed on the basis of MMG(5), Inoue(17), Hooft(18) and so on. Calcuations of manoeuvring motions for three kinds of typical characteristics, namely turning motion, zig-zag manoeuvre response and steady turning performance, are carried out. In order to examine the validity of the calculation method of this paper, simulations are run for seven merchant ships employed by Inoue(4). The computed results by present method are compared with full scale trials and Inoue's calculations(4). It can be concluded that the calculation method proposed in this paper is useful and pwoerful for prediction of characteristics of ship manoeuvring motions at the initial design phase or the application study on manoeuvring motions.

• 한국항해학회지
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• 제18권4호
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• pp.11-21
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• 1994

Final aim of this paper is a study on simulation of automatic steering of a ship in random seas. In order to achieve this aim, we need excitation due to random seas. The excitation may be estimated from energy spectrum of irregular waves and response functions of manoeuvring motion of a ship in regular waves. This paper deals with response functions of manoeuvring motion of a ship in regular waves. We discussed New Strip Method(NSM) of sway-yaw-roll coupled motions in regular waves. NSM is defined in space axes system and that has been used to predict seakeeping performance of a ship in waves. But ship manoeuvring is defined in body fixed axes system. So we cannot use NSM theory itself in predicting manoeuvring performance of a ship in waves. We introduced relationship between space axes system and body fixed axes system. And we developed modified NSM which was defined in body fixed axes system and was able to be used in manoeuvring motion of a ship in waves. We calculated sway and yaw response functions of manoeuvring motion of a bulk carrier in regular waves.

• 한국항해항만학회지
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• 제27권5호
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• pp.451-458
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• 2003

일반적으로 메타센터높이가 작은 선박이나 고속선의 경우에는 조종운동 시 큰 횡동요각을 유발하는 것으로 알려져 있다. 이러한 선박의 조종성능 예측 시에는 조종운동에 횡동요의 영향을 고려해야만 보다 정확한 결과를 얻을 수가 있다 즉, 조종운동을 다루는 전후동요, 좌우동요, 선수동요에 횡동요를 포함시키는 4자유도 운동방정식이 요구된다. 본 연구에서는 지금까지 여러 연구자들에 의해 제안되어 있는 4자유도 조종운동 수학모델을 검토 분석하고, 이들 실험자료를 재정리하여 보다 간결하고 실용적인 새로운 수학모델을 제안한다. 아울러 기존의 복잡한 수학모델과 새로운 수차모델에 의한 조종운동 시뮬레이션을 각각 수행하고 그 결과를 비교 검토하여 본 연구에서 제안한 수학모델의 유용성을 검증한다.

• 한국해양공학회지
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• 제37권4호
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• pp.129-136
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• 2023

To evaluate manoeuvring performance of merchant ships, the mathematical modeling group (MMG) or computational fluid dynamics (CFD) simulations are used. However, it is difficult to use the MMG to evaluate the manoeuvring performance of fishing vessels, thus research using CFD simulations is necessary. Also, since the course-changing and turning ability is crucial in fishing operations, a rudder design suitable for fishing vessels is necessary. This study designs a rudder using National Advisory Committee for Aeronautics (NACA) airfoil sections and evaluates its manoeuvring performance. A CFD model is used to evaluate the manoeuvring performance of the fishing vessel, and turning and zig-zag tests are conducted. The effectiveness of using CFD simulations based on Reynolds averaged Navier-Stokes equations to assess the manoeuvring performance of fishing vessels was validated. No significant difference was found in the manoeuvring performance for hull forms and rudder designs for course-changing ability. However, the original hull form showed superior turning performance. Among five rudders with varying aspect ratios and shapes, the rudder with 5.5% aspect ratio had the best turning performance. Regarding the rudder design for fishing vessels, NACA airfoil was employed, and a rudder aspect ratio of 5.5% based on the immersed hull side area is recommended.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제25권4호
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• pp.71-79
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• 2019

Purpose: The manoeuvring space at doors must be secured for users of walking aids, wheelchair users, stroller users, luggage carriers, etc., so clear criteria must be established. The korean standards for the manoeuvring space at doors need to be improved to present clear criteria depending on the type of entrance and the direction of opening and closing. Method: Korean standard, International Standard(ISO 21542, 2011), German Standard(DIN 18040-1, 2010), Austrian Standard(OENORM B 1600, 2017) and Swiss Standard(Norm SIA 500, 2009) were investigated and analyzed. A comprehensive improvement of the criteria for the manoeuvring space at doors is proposed. Results: The manoeuvring space at doors, which is essential for the disabled to use the door, shall be installed with a comprehensive consideration of the width of doors, the Circulation space, the direction of access, and the method of opening and closing of the door. Korean standards, such as the width of doors, the Circulation space, and the manoeuvring space at doors, are different from international and international standards, which require improvement of standards. The criteria for the manoeuvring space at doors shall be clearly improved so as not to be misinterpreted during the installation of doors and the BF-certification. Implication: The criteria for the installation of doors shall be presented as a comprehensive alternative through continued study of details. In addition, improvements in standards that reflect changes in international standards should be made.

• 대한조선학회논문집
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• 제47권6호
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• pp.776-781
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• 2010

In the ship-handling simulator, it is important for a ship manoeuvring model to represent the dynamic characteristic of a ship and to be simple for reducing calculation time. Especially, even if principal dimensions of a ship are given in initial design stage, or manoeuvring test data are only given by model or real ship's trials, simulations are often needed to check the manoeuvrability of a ship. In this paper, a simple manoeuvring model based on turning test data of a ship is mathematically developed. And the simulation results are verified by comparing with turning test results of a real ship.

• 대한조선학회논문집
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• 제52권5호
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• pp.407-417
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• 2015

For the more accurate prediction on manoeuvring performance of a ship at initial design phase, bare hull manoeuvring coefficients were estimated by RANS(Reynolds Averaged Navier-Stokes) based virtual captive model tests. Hydrodynamic forces and moment acting on the hull during static drift and harmonic oscillatory motions were computed with a commercial RANS code STAR-CCM+. Automatic and consistent mesh generation could be implemented by using macro functions of the code and user dependency could be greatly reduced. Computed forces and moments on KCS and KVLCC 1&2 were compared with the corresponding measurements from PMM(Planar Motion Mechanism) tests. Quite good agreement can be observed between the CFD and EFD results. Manoeuvring coefficients and IMO standard manoeuvres estimated from the computed data also showed reasonable agreement with those from the experimental data. Based on these results, we could confirm that the developed virtual captive manoeuvring model test process could be applied to evaluate manoeuvrability of a ship at the initial hull design phase.

• 한국항해항만학회지
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• 제29권3호
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• pp.189-194
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• 2005

선박이라는 거대한 물체를 항만 또는 조선소내의 안벽에 접안하거나 이로부터 이안시키는 작업은 도선사나 도크마스터의 고유한 업무로서 상당한 집중력과 고도의 위험성을 내포하고 있다. 이와 같은 접이안 작업 시에는 예선의 사용량이 많아지고, 본선이 저속으로 움직이므로 외력의 영향을 크게 받는다. 본 연구에서는 외력의 영향 특히 강풍 하에서 주로 예선을 이용하여 접이안 조종 작업을 수행할 수 있는 2차원 가상시스템은 구축하였다. 또한 조종위험도를 평가할 수 있는 객관적인 기준을 제안하고 이를 위해 시뮬레이션 실험은 수행하였다. 이 가상시스템을 이용하여 접이안 조종 작업을 수행한 결과 운항자가 주관적으로 체감한 위험의 정도를 수치화하여 표현한 주관적 평가와 조종운동과 관련된 주요 파라미터에 관련된 객관적인 지수와의 상관관계를 분석하여 조종위험도의 평가 기법에 대해 논의한다.

• 대한조선학회논문집
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• 제40권5호
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• pp.43-52
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• 2003

Two methods which estimate manoeuvring derivatives in the model of hydrodynamic force and moment acting on a manoeuvring ship using sea trial data were compared. One is the widely used parameter estimation method by using the Extended Kalman Filter (EKF), which estimates state variables of linearized state space model at every instant after dealing with the coefficients as the augmented state variables. The other one is the Estimation-Before-Modeling (EBM) technique, so called the two-step method. In the first step, hydrodynamic force of which dynamic model is assumed the third-order Gauss-Markov process is estimated along with motion variables by the EKF and the modified Bryson-Frazier smoother. Then, in the next step, manoeuvring derivatives are identified through the regression analysis. If the exact structure of hydrodynamic force could be known, which was an ideal case, the EKF method would be regarded as being more superior compared to the EBM technique. However the EBM technique was more robust than the EKF method from a realistic point of view where the assumed model structure was slightly different from the real one.

• 대한조선학회논문집
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• 제57권6호
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• pp.331-344
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• 2020

Ship's hydrodynamic coefficients in manoeuvring equations are generally derived by captive model tests or numerical calculations. Empirical formulas have been also proposed in some previous researches, which were useful for practical predictions of hydrodynamic coefficients of a ship by using main dimensions only. In this study, ship's hydrodynamic coefficients based on empirical formulas were optimized by using its free running test data. Eight manoeuvring performance indices including steady turning radius, reach in zig-zag as well as well-known IMO criteria indices are selected in order to compare simulation results with free runs effectively. Sensitivities of hydrodynamic coefficients on manoeuvring performance indices are analyzed. And hydrodynamic coefficients are tuned within fixed bounds in order of sensitivity so that they are tuned as little as possible. Linear and nonlinear coefficients are successively tuned by using zig-zag and turning performance indices. Trajectories and velocity components by simulations with tuned hydrodynamic coefficients are in good agreements with free running tests. Tuned coefficients are also compared with coefficients by captive model tests or RANS calculations in other previous researches, and the magnitudes and signs of tunes are discussed.