• International Journal of Naval Architecture and Ocean Engineering
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• 제6권3호
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• pp.700-714
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• 2014

This study aims to identify the relations between seakeeping characteristics and hull form parameters for YTU Gulet series with cruiser stern. Seakeeping analyses are carried out by means of a computer software which is based on the strip theory and statistical short term response prediction method. Multiple regression analysis is used for numerical assessment through a computer software. RMS heave-pitch motions and absolute vertical accelerations on passenger saloon for Sea State 3 at head waves are investigated for this purpose. It is well known that while ship weight and the ratios of main dimensions are the primary factors on ship motions, other hull form parameters ($C_P$, $C_{WP}$, $C_{VP}$, etc.) are the secondary factors. In this study, to have an idea of geometric properties on ship motions of gulets three different regression models are developed. The obtained outcomes provide practical predictions of seakeeping behavior of gulets with a high level of accuracy that would be useful during the concept design stage.

• 대한조선학회논문집
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• 제40권3호
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• pp.16-21
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• 2003

Seakeeping performance of container ships is investigated in view of increase of their size in terms of TEU. Recent appearance of post Panamax class containers resulted in increase of GM, so increase of possibility of resonant motion in waves is expected accordingly. Ship motions of various classes of TEU containers were calculated for various sea states and heading angles in order to assess seakeeping characteristics according to increase of size of the ships. It was found that roll motion of post Panamax containers increase due to resonance as sea state becomes rougher. The possibility of controlling roll motion by changing main particulars such as L, B, and T is investigated as well.

• 한국항해항만학회지
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• 제42권6호
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• pp.395-405
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• 2018

한국형 e-Navigation의 내항성 안전 모듈은 운항 중인 선박을 실시간으로 모니터링하고 내항성의 이상 상태를 사전에 경고함으로써 선박의 안정성을 확보하는 선내 원격 모니터링 서비스 중 하나이다. 일반적으로 선박설계를 위한 내항성능은 주어진 조건에서 선체 운동 시뮬레이션을 수행하여 평가하여 왔다. 하지만 운항 중 선박의 내항성능을 실시간으로 평가하기 위해 이러한 시뮬레이션을 실제 운항조건에 맞추어 수행하는 것은 계산시간의 한계로 인해 현실적이지 않다. 본 연구에서는 기계학습 기반의 근사모델을 활용하여 선박의 내항성능 평가 요소들 중 하나인 횡동요 운동특성을 합리적으로 보다 빠르게 예측하는 방법을 소개하고자 한다. 다양한 학습 기법과 데이터의 샘플링 조건을 적용하여, 얻어진 근사모델의 결과와 운동해석 결과의 오차가 거의 1% 내로 일치함을 보였다. 따라서 이러한 방법을 활용하면 선박의 실시간 내항성능을 평가하는데 효율적으로 사용할 수 있을 것으로 판단된다.

• 한국해양공학회지
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• 제33권6호
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• pp.632-640
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• 2019

Desalination plant ships have been recently regarded as one of the probable solutions for drought seasons in many countries. Because desalination plants should be mounted on the desalination ships and special purpose storages such as salty waste water tanks are necessary, onboard and compartment arrangements would be distinguished from those of other conventional commercial ships. This paper introduces some basic design procedure including resistance/propulsion and seakeeping performances. The ship lines were improved step by step after modification of the ship lines and verification of resistance/propulsion performances using computational fluid dynamics (CFD). After finalization of the ship lines, the seakeeping performance was also evaluated to check motion behaviors and drive wave-induced loads such as the wave shear force and bending moment. It was proved that the predicted long-term vertical wave shear force and bending moment were significantly less than the rule-based ones, thus it is expected that the deliverables of this study will reduce the construction cost of desalination plant ships.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2003년도 춘계학술발표회
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• pp.31-40
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• 2003

There are winds and waves in the sea, and they are changed frequently in accordance with the weather. By analyzing them which have the closest relation to the ship's safe voyage. evaluating the seakeeping performance and then taking a proper action, navigators should carry out safe navigation on the sea. A ship in seaways suffers continuous disturbances by irregular waves, and ship motions with irregular waves cannot be easily described as a system model which is adequate to a control system. But, in general, for seakeeping analysis, ship motions in irregular seas can be estimated by the superposition of the motion responses in regular wave components of the sea spectrum. After comparing and analyzing the winds and waves in major sea areas, this paper evaluates the navigational safety of ships on the Korean coast with potential dangerous seakeeping performance using the weather information provided by land. The conclusion is as follows : (1) It is possible that the safety of ships could be secured more accurately by evaluating the seakeeping performance of ships. (2) When the weather is bad, the departure of ships could be controlled by evaluating the navigational safety of ships. (3) When a ship is placed in commission in any area, this evaluation could be used to decide the type and size of ship in use.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2010년도 춘계학술대회
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• pp.385-386
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• 2010

선박의 상하동요 및 종동요 간의 내항성능은 승객에게 피로감을 주며, 적재된 화물과 선체에 탑재된 재설비에 구조적 하중을 가져오게 된다. 이러한 점을 개선하기 위해 소형 카타마란 파워요트 설계시 해당 실적선 조사와 선저형상을 결정하여 선형을 설계하였다. 본 연구에서는 국내 연안의 해양환경에 대한 기초자료를 토대로 운동성능 해석조건을 선정하였다. 이를 통해 카타마란형 레저선박의 운동성능을 선속에 따라 고찰하였다. 파도와 선박의 만남각에 따른 내항성능을 추정하여, 파랑의 만남주파수에 대한 응답진폭비와 운동성능이 우수한 영역에 대해서 평가하였다.

• 한국항해항만학회지
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• 제28권3호
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• pp.207-211
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• 2004

LMTT(Linear Motor-based Transfer Technology)는 항만 자동화를 위한 컨테이너 터미널용 수평 이송 장치이며, rail과 shuttle car(mover)에 부착된 stator module로 구성된 PMLSM(Permanent Magnetic Linear Synchronous Motor)에 의해 구동된다. 본 논문은 inner beam과 outer beam의 높이비가 LMTT용 shuttle car의 frame 강도 및 강성에 미치는 영향을 살펴보았다. 설계변수는 inner beam의 단면형상 및 높이비로 설정하였으며, 유한요소해석을 통하여 설계변수가 frame의 강도 및 강성에 미치는 영향을 살펴보았다.

• 해양환경안전학회지
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• 제9권1호
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• pp.41-50
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• 2003

한국 연안의 각 항로에 취항하고 있는 대표적인 선형의 여객선들을 대상으로, 각 선형별로 선체운동 계산, 내항성능을 분석하여 선박의 안전성을 평가하였다. 이를 위하여 선박의 안전운항과 가장 밀접한 관련을 갖는 바람과 파랑을 주요 해역별로 비교 분석하였다. 이러한 기강정보를 입력요소로 하여 주요해역을 항행하는 대표적인 선형의 여객선들에 대하여 수치 시뮬레이션을 실시하여 여객선의 항해안정성을 평가하였다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제5권1호
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• pp.161-177
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• 2013

High-speed vessels require good resistance and seakeeping performance for safe operations in rough seas. The resistance and seakeeping performance of high-speed vessels varies significantly depending on their hull forms. In this study, three planing hulls that have almost the same displacement and principal dimension are designed and the hydrodynamic characteristics of those hulls are estimated by high-speed model tests. All model ships are deep-V type planing hulls. The bows of no.2 and no.3 model ships are designed to be advantageous for wave-piercing in rough water. No.2 and no.3 model ships have concave and straight forebody cross-sections, respectively. And length-to-beam ratios of no.2 and no.3 models are larger than that of no.1 model. In calm water tests, running attitude and resistance of model ships are measured at various speeds. And motion tests in regular waves are performed to measure the heave and pitch motion responses of the model ships. The required power of no.1 (VPS) model is smallest, but its vertical motion amplitudes in waves are the largest. No.2 (VWC) model shows the smallest motion amplitudes in waves, but needs the greatest power at high speed. The resistance and seakeeping performance of no.3 (VWS) model ship are the middle of three model ships, respectively. And in regular waves, no.1 model ship experiences 'fly over' phenomena around its resonant frequency. Vertical accelerations at specific locations such as F.P., center of gravity of model ships are measured at their resonant frequency. It is necessary to measure accelerations by accelerometers or other devices in model tests for the accurate prediction of vertical accelerations in real ships.

• 한국항해항만학회지
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• 제31권10호
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• pp.905-910
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• 2007

최근에 선박이 대형화, 고속화되면서 선수 충격파 영향으로 인하여 선체 또는 화물에 잦은 손상을 초래하기도 하고, 극판적인 상황에서는 선박이 절단되기도 한다. 본 논문에서는 내항성능 평가요소 중 하나인 상하가속도 값을 선교에 설치된 선체감시장치를 이용하여 해상상태별 변화량을 계측하고, 이를 모형시험 및 이론계산 결과와 상호 비교하였다. 또한 ITTC에서 제시하는 내항성능 기준치와도 비교함으로써 실습선 한바다호의 내항성능을 확인하였다. 이러한 결과는 앞으로 경험할 수 있는 다양한 해상상태에서의 작업가능성 및 위험성 정도의 예측을 가능하게 함으로써 선박의 안전운항에 큰 도움이 될 것으로 판단되며, 또한 다양한 실선계측 자료를 통하여 조선소에서는 보다 우수한 성능의 선박 건조가 가능하리라 본다.