• Title/Summary/Keyword: Hydrodynamic Interaction forces

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The Interaction Effect Acting on a Vessel in the Proximity of Bank Wall (측벽근방을 항해하는 대형선박에 미치는 측벽의 영향)

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    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.04a
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    • pp.197-202
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    • 2004
  • It is well known that the hydrodynamic interaction forces between ship and bank wall affect ship manoeuvring motion. This paper deals with the interaction effect acting on a ship navigating closely in the proximity of bank wail. In this paper, the calculation method based on the slender body theory for estimation of the hydrodynamic interaction forces between ship and bank wail is applied. The hydrodynamic interaction forces acting on a ship during passing through the proximity of the bank wail are predicted to evaluate an influence of these interaction forces on ship manoeuvrability. The calculation method used in this paper will be useful for prediction of ship manoeuvrability at the initial stage of design, for automatic control system of ship in confined waterways, for discussion of marine traffic control system and for construction of harbour.

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The Interaction Effect Acting on a Ship Hull in the Proximity of Bank Wall (측벽근방을 항해하는 대형선박에 미치는 측벽의 영향)

  • Lee, Chun-Ki;Park, Hain-Il
    • Journal of Navigation and Port Research
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    • v.28 no.5
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    • pp.333-337
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    • 2004
  • It is well known that the hydrodynamic interaction forces between ship and bank wall affect ship manoeuvring motion This paper deals with the interaction effect acting on a ship navigating closely in the proximity of bank wall. In this paper, the calculation method based on the slender body theory for estimation of the hydrodynamic interaction forces between ship and bank wall is applied. The hydrodynamic interaction forces acting on a ship during passing through the proximity of the bank wall are predicted to evaluate an influence of these interaction forces on ship manoeuvrability. The calculation method used in this paper will be useful for prediction of ship manoeuvrability at the initial stage of design, for automatic control system of ship in confined waterways, for discussion of marine traffic control system and for construction of harbour.

A Study on the Hydrodynamic Interaction Forces between Ship and Bank Wall in the Proximity of Bank (측벽부근을 항해하는 선박과 측벽간의 상호 간섭력에 관한 연구)

  • Lee, Chun-Ki;Kang, Il-Kwon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.40 no.1
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    • pp.73-77
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    • 2004
  • It is well known that the hydrodynamic interaction forces between ship and bank wall affect ship manoeuvring motions. In this paper, the calculation method based on the slender body theory for estimation of the hydrodynamic interaction forces between ship and bank wall is investigated. The numerical simulations on hydrodynamic interaction force acting on a ship in the proximity of bank wall are carried out by using this theoretical method. The theoretical method used in this paper will be useful for practical prediction of ship manoeuvrability at the initial stage of design, for discussion of marine traffic control system and for automatic control system of ship in confined waterways.

The Hydrodynamic Interaction Effects between Two Barges on the Motion Responses (상호작용을 고려한 두 바아지의 운동응답)

  • S.P.,Ann;K.P.,Rhee
    • Bulletin of the Society of Naval Architects of Korea
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    • v.24 no.1
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    • pp.29-34
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    • 1987
  • In this paper, a three dimensional singularity distribution method is applied to investigate the hydrodynamic interactions between two barges floating on a free surface of a deep water. The results show that the hydrodynamic interaction forces are important in the calculation responses of two barges floating in each other's vicinity. Furthermore the trends of hydrodynamic forces due to the motion of body itself are different from those of a single barged, and the motions of the seaward barge can sometimes exceed those of the seaward barged.

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Hydroelastic Response of VLFS with Submerged-Plate Using Modified Hydrodynamic Coefficients

  • Lee, Sang-Min
    • Journal of Navigation and Port Research
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    • v.31 no.7
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    • pp.569-578
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    • 2007
  • The primary objective of this study is to present a modified method of hydroelastic analysis and application of it to the VLFS with submerged plate. The modal analysis method is applied to the VLFS with the submerged plate using the modified hydrodynamic coefficients. Namely, the wave exciting forces are modified by the transmission wave coefficients, while the interaction factor is used for the modification of radiation forces. To validate the proposed method, comparisons between the numerical calculations and experimental data have been carried out for the deflections of VLFS, and it shows good agreement between the calculation and experiment. The results presented in this study demonstrate that the elastic response of the VLFS is strongly affected by the hydrodynamic interaction induced by the submerged plate. As a result, we can confirm that the submerged plate is useful for reducing the hydroelastic deflection of VLFS, and the proposed method is valuable for predicting the elastic response of VLFS with attached the submerged plate.

An Experimental Study on Ship-Bank Hydrodynamic Interaction Forces

  • Lee, Chun-Gi;Mun, Seong-Bae;Jeong, Yeon-Cheol;Jeong, Tae-Gwon;Lee, Dong-Seop;Gang, Il-Gwon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2013.06a
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    • pp.15-16
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    • 2013
  • This paper is mainly concerned with the ship-bank interaction by model test. The experiments for the characteristics of hydrodynamic interaction forces and moments between vessel and bank with a mound were carried out in the seakeeping and maneuvering basin.

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An Experimental Study on Ship-Bank Hydrodynamic Interaction Forces (선박에 작용하는 측벽영향에 관한 실험적 연구)

  • Lee, Chun-Ki
    • Journal of Navigation and Port Research
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    • v.37 no.3
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    • pp.251-256
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    • 2013
  • This paper is mainly concerned with the ship-bank interaction by model test. The experiments for the characteristics of hydrodynamic interaction forces and moments between vessel and bank with a mound were carried out in the seakeeping and maneuvering basin. A series of tests were carried out with ship model in parallel course along a vertical sidewall with a mound with varying lateral spacing between model ship and sidewall, length of sidewall and water depth. From the experimental results, it indicated that the hydrodynamic interaction effects increase as length of sidewall with a mound increases. Furthermore, for lateral spacing less than about 0.2L between vessel and bank, it can be concluded that the bank effects increase largely as the lateral spacing between vessel and bank decreases. However, for spacing between vessel and bank more than about 0.3L, the interaction effects increase slowly as lateral spacing decreases. Also, for the water depth to draft ratio(h/d) less than about 1.5, the hydrodynamic interaction effects increase dramatically as h/d decreases.

Hydrodynamic forces on blocks and vertical wall on a step bottom

  • Mondal, Ramnarayan;Alam, Md. Mahbub
    • Wind and Structures
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    • v.30 no.5
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    • pp.485-497
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    • 2020
  • A study, using potential water wave theory, is conducted on the oblique water wave motion over two fixed submerged rectangular blocks (breakwaters) placed over a finite step bottom. We have considered infinite and semi-infinite fluid domains. In both domains, the Fourier expansion method is employed to obtain the velocity potentials explicitly in terms of the infinite Fourier series. The unknown coefficients appearing in the velocity potentials are determined by the eigenfunction expansion matching method at the interfaces. The derived velocity potentials are used to compute the hydrodynamic horizontal and vertical forces acting on the submerged blocks for different values of block thickness, gap spacing between the two blocks, and submergence depth of the upper block from the mean free surface. In addition, the wave load on the vertical wall is computed in the case of the semi-infinite fluid domain for different values of blocks width and the incident wave angle. It is observed that the amplitudes of hydrodynamic forces are negligible for larger values of the wavenumber. Furthermore, the upper block experiences a higher hydrodynamic force than the lower block, regardless of the gap spacing, submergence depth, and block thickness.

Wave induced motion of a triangular tension leg platforms in deep waters

  • Abou-Rayan, A.M.;El-Gamal, Amr R.
    • Ocean Systems Engineering
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    • v.3 no.2
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    • pp.149-165
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    • 2013
  • Tension leg platforms (TLP's) are highly nonlinear due to large structural displacements and fluid motion-structure interaction. Therefore, the nonlinear dynamic response of TLP's under hydrodynamic wave loading is necessary to determine their deformations and dynamic characteristics. In this paper, a numerical study using modified Morison Equation was carried out in the time domain to investigate the influence of nonlinearities due to hydrodynamic forces and the coupling effect between all degrees of freedom on the dynamic behavior of a TLP. The stiffness of the TLP was derived from a combination of hydrostatic restoring forces and restoring forces due to cables and the nonlinear equations of motion were solved utilizing Newmark's beta integration scheme. The effect of wave characteristics was considered.

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.