• Title/Summary/Keyword: Restricted waterway

Search Result 9, Processing Time 0.03 seconds

Wave Field Near a Vessel in Restricted Waterway

  • Kim, Chang-Je
    • Journal of Navigation and Port Research
    • /
    • v.35 no.7
    • /
    • pp.557-562
    • /
    • 2011
  • Shipwaves can have harmful effects on people who are using riverside and cause bank erosion, bank structures destruction in restricted waterways. The wave field near a vessel is consisted of a combination of a primary and secondary wave system in a shallow or restricted waterway. The water level depression(squat) and return current beside the hull are called the primary wave system. The secondary wave system, that is the wave height originates from a local disturbance point such as the bow of the ship. This study aims at investigating the characteristics of the wave field around a vessel in a restricted water in relation to navigation experimentally and theoretically. The return current and squat with a correction factor can be newly evaluated and the almost same high-sized wave heights take place on the whole waterway in a restricted water without regard to the distance from the sailing line.

A numerical study on ship-ship interaction in shallow and restricted waterway

  • Lee, Sungwook
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • v.7 no.5
    • /
    • pp.920-938
    • /
    • 2015
  • In the present study, a numerical prediction method on the hydrodynamic interaction force and moment between two ships in shallow and restricted waterway is presented. Especially, the present study proposes a methodology to overcome the limitation of the two dimensional perturbation method which is related to the moored-passing ship interaction. The validation study was performed and compared with the experiment, firstly. Afterward, in order to propose a methodology in terms with the moored-passing ship interaction, further studies were performed for the moored-passing ship case with a Reynolds Averaged Navier-Stokes (RANS) calculation which is using OpenFOAM with Arbitrary Coupled Mesh Interface (ACMI) technique and compared with the experiment result. Finally, the present study proposes a guide to apply the two dimensional perturbation method to the moored-passing ship interaction. In addition, it presents a possibility that the RANS calculation with ACMI can applied to the ship-ship interaction without using a overset moving grid technique.

Numerical Study on Characteristics of Ship Wave According to Shape of Waterway Section

  • Hong Chun-Beom;Lee Sang-Min
    • Journal of Mechanical Science and Technology
    • /
    • v.19 no.12
    • /
    • pp.2263-2269
    • /
    • 2005
  • The ship wave phenomena in the restricted waterway were investigated by a numerical analysis. The Euler and continuity equations were employed for the present study. The boundary fitted and moving grid system was adopted to enhance the computational efficiency. The convective terms in the governing equations and the kinematic free surface boundary condition were solved by the Constrained Interpolated Profile (CIP) algorithm in order to solve accurately wave heights in far field as well as near field. The advantage of the CIP method was verified by the comparison of the computed results by the CIP and the Maker and Cell (MAC) method. The free surface flow simulation around Wigley hull was performed and compared with the experiment for the sake of the validation of the numerical method. The present numerical scheme was applied to the free surface simulation for various canal sections in order to understand the effect of the sectional shape of waterways on the ship waves. The wave heights on the side wall and the shape of the wave patterns with their characteristics of flow are discussed.

A Study on the Safe Manoeuvring between Vessels under the Strong Current in Restricted Waterways (제한수역에서 강조류하에 근접항행중인 선박간의 안전조선(安全操船)에 관한 연구)

  • Lee, Chun-Ki;Yoon, Jeom-Dong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2007.12a
    • /
    • pp.77-78
    • /
    • 2007
  • The aim if the present research is to develop a guideline if a safe conducting distance according to separated distance and velocity if the two vessels to navigate safely in restricted waterways. The authors studied the hydrodynamic forces between two vessels running closely and calculated safe conducting distances according to separated distances and speeds if the vessels under the condition if wind and strong current.

  • PDF

The Interaction Effects Between Two Vessels in the Proximity of Bank Wall in Restricted Waterways (제한수역에서 측벽부근을 항해하는 두 선박간의 상호영향)

  • Lee Chun- Ki
    • Journal of Navigation and Port Research
    • /
    • v.29 no.1 s.97
    • /
    • pp.17-22
    • /
    • 2005
  • The manoeuvring of vessels and hydrodynamic interaction between them and bank wall in restricted waterways have been treated as important factors in channel design and safe piloting in the waterway areas. This paper examines the interaction forces and moments acting on two vessels running closely in the proximity of bank wall. The object of this paper is to propose a guideline of safe velocity of vessels and distance between them for navigating safely in confined sea areas.

Estimation of the Traffic Flow in the Korea Coastal Waterway by Computer Simulation (우리나라 연안의 해상교통관제시스템 설치를 위한 기초연구 시뮬레이션에 의한 우리나라 연안의 해상교통량 추정)

  • 구자윤;박양기;이철영
    • Journal of the Korean Institute of Navigation
    • /
    • v.12 no.1
    • /
    • pp.85-112
    • /
    • 1988
  • From the point of view of safety of life and property at sea and the protection of the marine environment, the Vessel Traffic Management System along the Korea coastal waterway is inevitably introduced. But the establishing priority per area must be evaluated under the restricted budget. In this case, the estimated traffic flow has a major effect on priority evaluation. In the former paper , an algorithm was proposed for estimating the trip distribution between each pair of zones such as harbours and straits. This paper aims to formulate a simulation model for estimating the dynamic traffic flow per area in the Korea coastal waterway. The model consists of the algorithm constrined by the statistical movement of ships and the observed data, the regression analysis and the traffic network evaluations. The processed results of traffic flow except fishing vessel are summarized as follows ; 1) In 2000, the traffic congestions per area are estimated, in proportion of ship's number (tonnage), as Busan area 22.3%(44.5%), Yeosu area 19.8%(11.2%), Wando-Jeju area18.1%(6.8%), Mokpo area 14.9%(9.9%), Gunsan area 9.1%(9.3%), Inchon area 8.1%(7.7%), Pohang area 5.5%(8.5%), and Donghae area 2.2%(2.1%). 2) For example in Busan area, the increment of traffic volume per annum is estimated 4, 102 ships (23 million tons) and the traffic flow in 2000 is evaluated 158, 793 ships (687 million tons). 3) consequently, the increment of traffic volume in Busan area is found the largest and followed by Yeosu, Wando-Jeju area. Also, the traffic flow per area in 2000 has the same order.

  • PDF

A Study on Flow Zone Development and Bottom Change by Propeller Jets from Ships (선박추진기에 의한 흐름발달과 해저면변화에 대한 연구)

  • 이지훈;이중우
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2002.11a
    • /
    • pp.139-145
    • /
    • 2002
  • The flow zone through propeller jets are used in evaluating the environmental and constructional effects of navigation on the waterway. It relies on the characteristics of ships and water depth. A numerical model using the momentum theory of the propeller and Shield's diagram was developed in a restricted waterway. Equations for discharge are presented based on thrust coefficients and propeller speed and are the most accurate means of defining discharge. Approximate methods for discharge are developed based on applied ship's power. Equations for discharge are as a function of applied power, propeller diameter, and ship speed. Water depth of the waterway and draft of the shop are also necessary for the calculation of the grain size of the initial motion. The velocity distribution of discharge from the propeller was simulated by the Gaussian normal distribution function. The shear velocity and shear stress were from the Sternberg's formula. Case studies to show the influence of significant factors on sediment movement induced by the ship's propeller at the channel bottom are presented.

  • PDF

On the Manoeuvring Motion Considering the Interaction Forces in Confined Waters

  • Lee, Chun-Ki;Kang, Il-Kwon
    • Journal of Navigation and Port Research
    • /
    • v.27 no.6
    • /
    • pp.639-643
    • /
    • 2003
  • The emphasis is put on the detailed knowledge on manoeuvring characteristic for the safe navigation while avoiding terrible collision between ships and on the guideline to the design and operation of the ship-waterway system The numerical simulation of manoeuvring motion was carried out parametrically for different ship types, ship-velocity ratios, separation and stagger between ships. As for the calculation parameters, the ratios of velocity difference (hereafter, $U_2$/$U_1$ ) between two ships were considered as 0.6, 1.2, 1.5. From the inspection of this investigation, it indicates the following result. Considering the interaction force only as parameter, the lateral distance between ships is necessarily required for the ship-velocity ratio of 1.2, compared to the cases of 0.6 and 1.5 regardless of the ship types. Furthermore, regardless of the ship-velocity ratio, an overtaking and overtaken vessel can be manoeuvred safely without deviating from the original course under the following conditions: the lateral distance between two vessels is approximately kept at 0.5 times of ship-length and 5 through 10. degrees of range in maximum rudder angle. The manoeuvring characteristic based on this investigation will be very useful for keeping the safety of navigation from the practical point of ships design and traffic control in restricted waterways.

A study on the problems in appling CIF, Incoterms 1990 into the contract of sale. (1990년(年) 인코텀즈에 따른 CIF조건(條件)의 활용상(活用上)의 문제점(問題點))

  • Choi, Myung-Kook
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
    • /
    • v.6
    • /
    • pp.11-51
    • /
    • 1993
  • This study is focused on the problems and the suggestions of proper ideas for solving them which are arisen from appling CIF, Incoterms 1990 into the contract of sale after reviewing of the contents of traditional CIF contract and the main changes of CIF, Incoterms 1990. This study summerized as follows: First, when the seller provide the buyer with non-negotiable sea waybill or inland waterway document instead of negotiable bill of lading, it is my feeling that the essence of symbolic delivery in traditional CIF contract is fading. And if the buyer has paid for the goods in advance, or a bank wishes to use the goods as security for a loan extended to the buyer, it is not sufficient that the buyer or the bank be named as consignee in a non-negotiable document. This is true because the seller by new instractions to the carrier could replace the named consignee with someone else. To protect the buyer or the bank it is therefore necessary that the original instructions from the seller to the carrier to deliver the goods to the named consignee be irrevocable. Second, CIF term can only be used for sea and inland waterway transport. When the ship's rail serves no practical purposes such as in the case of roll-on/roll-off or container traffic, CIP term instead of CIF term is more appropriate to use. Third, the EDI method still contains many legal and technical problems to be solved in order to be used thoroughly' in the international sale of goods. Therefore, the parties wishing to replace the traditional paper-based trade documents by electronic messages must exchange the agreement on EDI each other in order to prevent and sol ye unexpected problems. Forth, it may be that the goods are to be carried in bulk without such marking or naming of consignee as would amount to appropriation. Then the risk will not pass until effective appropriation has been made. Therefore, the seller needs to appropriate by issuing of separate bills of lading or delivery orders for parts of the bulk cargo. And in case the goods are bought while they are carried at sea, some problems on the passing of risk would arise. One possibility is that the buyer might have to assume risks which have already occured at the time when the contract of sale is entered into force. The other possibility would be to let the pissing of the risk concide with the time when the contract of sale is concluded. The parties are advised to ascertain the applicable law and any solution which might follow there form. Finally, Incoterms are restricted to deal with the main principles for the division of functions, costs and risks between the parties and the rest is left to their individual contract as supplemented by the custom of the trade, the individual terms of the contract of sale and the applicable law. Thus, the parties are advised to ascertain the applicable law on their individual contract of sale in order to solve the problems on the transfer of property, the remedy and so on.

  • PDF