• Title/Summary/Keyword: Interaction effects between two vessels

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A Study on the Minimum Safe Distance between Two Vessels in Confined Waters

  • Lee, Chun-Ki;Moon, Serng-Bae
    • Journal of Navigation and Port Research
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    • v.38 no.6
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    • pp.561-565
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    • 2014
  • This paper is mainly concerned with the interaction effects between two vessels and sidewall with a mound. Experimental study on hydrodynamic forces between ship and sidewall with a mound was already shown in the previous paper, measured by varying the distances between ship and sidewall. The ship maneuvering simulation was conducted to find out the minimum safe distance between vessels, which is needed to avoid sea accident in confined waters. From the inspection of this investigation, it indicates the following result. When and if one vessel passes the other vessel through the proximity of sidewall with a mound, the spacing between two vessels is needed for the velocity ratio of 1.2, compared to the case of 1.5. Also, for the case of ship-size estimation, the ship maneuvering motion is more affected by interaction effects for the overtaken small vessel, compared to the overtaking large vessel.

The investigation of ship maneuvering with hydrodynamic effects between ships in curved narrow channel

  • Lee, Chun-Ki;Moon, Serng-Bae;Jeong, Tae-Gweon
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.8 no.1
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    • pp.102-109
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    • 2016
  • The hydrodynamic interaction between two large vessels can't be neglected when two large vessels are closed to each other in restricted waterways such as in a harbor or narrow channel. This paper is mainly concerned with the ship maneuvering motion based on the hydrodynamic interaction effects between two large vessels moving each other in curved narrow channel. In this research, the characteristic features of the hydrodynamic interaction forces between two large vessels are described and illustrated, and the effects of velocity ratio and the spacing between two vessels are summarized and discussed. Also, the Inchon outer harbor area through the PALMI island channel in Korea was selected, and the ship maneuvering simulation was carried out to propose an appropriate safe speed and distance between two ships, which is required to avoid sea accident in confined waters. From the inspection of this investigation, it indicates the following result. Under the condition of $SP_{12}{\leq}0:5L$, it may encounter a dangerous tendency of grounding or collision due to the combined effect of the interaction between ships and external forces. Also considering the interaction and wind effect as a parameter, an overtaken and overtaking vessel in narrow channel can navigate while keeping its own original course under the following conditions; the lateral separation between two ships is about kept at 0.6 times of ship length and 15 degrees of range in maximum rudder angle. On the other hand, two ships while overtaking in curved narrow channel such as Inchon outer harbor in Korea should be navigated under the following conditions; $SP_{12}$ is about kept at 1.0 times of ship length and the wind velocity should not be stronger than 10 m/s.

A Study about the interactions of vessels running parallely in proximity to one another and safe conducting of them in restricted waterways (제한수역에서 근접 항해하는 선박의 상호작용과 안전항해거리에 관한 연구)

  • Lee Chun-Ki
    • Journal of Navigation and Port Research
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    • v.29 no.8 s.104
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    • pp.647-652
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    • 2005
  • When a vessel passes near a channel boundary, the boundary creates forces and moments acting on the vessel. With the same reason passing of two vessels closely gives same effects to each other. The principal difference between the above two cases is that the channel boundary is long and constant shape compared to those of vessels. The interaction forces and moments between two vessels could be assumed to be functions of the longitudinal distance $chi_0$, transverse distance $y_0$ and speeds of the two vessels. Passage of one vessel close to another is important operationally from the viewpoint of replenishment at sea, avoidance of collisions and passage of two vessels in restricted channels. The authors studied the interactions between two vessels running closely and calculated safe conducting distances according to separated distances and speeds of the two vessels.

A Study about the interactions of vessels running parallely proximity to one another and safe conducting of them (병항(竝航) 2선박간의 상호작용과 안전항과(安全航過)에 관한 연구)

  • Lee Chun-Ki;Yoon Jeom-Dong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2005.10a
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    • pp.11-16
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    • 2005
  • When a vessel passes near a channel boundary, the boundary creates forces and moments acting on the vessel. With the same reason passing of two vessels closely gives same effects to each other. The principal. difference between the above two cases is that the channel boundary is long and constant shape compared to those of vessels. The interaction forces and moments between two vessels could be assumed to be functions of the longitudinal distance $x_0$, transverse distance $y_0$ and speeds of the two vessels. Passage of one vessel close to another is important operationally from the viewpoint of replenishment at sea, avoidance of collisions and passage of two vessels in restricted channels. The authors studied the interactions between two vessels running closely and calculated safe conducting distances according to separated distances and speeds of the two vessels.

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

  • Lee Chun-Ki;Yoon Jeom一Dong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.11a
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    • pp.49-55
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    • 2004
  • 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 water areas. This paper examines the interaction forces and moments acting on two vessels running closely in the proximity if bank wall. The object if this paper is to propose a guideline of safe velocity if vessels and distance between them for navigating safely in confined sea areas.

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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
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    • v.29 no.1 s.97
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    • pp.17-22
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    • 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.

A Study on the Minimum Safe Distance between Two Vessels in Confined Waters

  • Lee, Chun-Gi;Mun, Seong-Bae;Jeong, Tae-Gwon;Jeong, Yeon-Cheol;Gong, Gil-Yeong;Lee, Jun-Ho
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2013.10a
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    • pp.56-57
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    • 2013
  • This paper is mainly concerned with the interaction effects between two vessels and sidewall with a mound. Experimental study on hydrodynamic forces between ship and sidewall with a mound was already shown in the previous paper, measured by varying the distances between ship and sidewall. The ship maneuvering simulation was conducted to find out the minimum safe distance between vessels, which is needed to avoid sea accident in confined waters.

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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
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    • 2007.12a
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    • pp.77-78
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    • 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.

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The Difference Between Nicardipine and Its Enantiomers on Inhibiting Vasoconstriction of Isolated Rabbit Thoracic Artery

  • Wang Sicen;He Lang chong;Yun Sofeng
    • Archives of Pharmacal Research
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    • v.28 no.3
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    • pp.319-324
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    • 2005
  • The present study was designed to study the difference effects between nicardipine and its two enantiomers on thoracic artery of rabbit. A high-performance liquid chromatographic method was used to prepare the two enantiomers of nicardipine. The thoracic artery of rabbit was removed. The vessels were cut into 3 mm in width and 15 mm in length spiral strips and immersed into tissue baths. The concentration-response curves of nicardipine and its enantiomers were obtained by cumulative administration of the vasoconstrictors. Nicardipine and the enantiomers could shift the dose-response curves of NE, KCI or CaCl$_2$ to right in a nonparallel manner and decrease the maximum effective in a concentration-depended manner, respectively. The pD$_2$' value of R-(-)-nicardipine showed significantly effective than that of nicardipine and S-(+)-nicardipine (P<0.01). There was not obviouse difference between the pD$_2$' value of nicardipine and S-(+)-nicardipine (P>0.05). The results demonstrate that the stereoselective interaction between R-(-)-nicardipine and L-calcium channel receptor is more stronger than that of S-(+)-nicardipine.