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Experiment on pressure characteristics of submerged floating tunnel with different section types under wave condition

Li Q., Jiang S., Chen X.

Polish Maritime Research

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2018

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S 3

54--60

EN

Submerged floating tunnel (SFT for short) is a special underwater traffic structure, and wave load is one of the main environmental loads of SFT structure. In this paper, the 1:60 physical model test of three kinds of SFT in a two-dimensional wave flume is tested. The effects of random irregular waves on the SFT structure under different wave heights and periods are discussed. The study shows that: (1) Compared with circular and polygonal sections, there are multiple local peaks in the elliptical section during the period. with the increase of wave height, the number of local peaks also increases. It suggests that the rotational moment plays an important role in the elliptical section which has a relatively small depth-width ratio. (2) The position of the maximum and minimum pressure in the three kinds of SFT sections is consistent. Their vertical wave forces are all larger than their horizontal wave forces. The increase of vertical wave force relative to horizontal wave force in polygon section is larger than that in elliptical section, and the difference in the circular section is the smallest. (3) Under the same traffic condition, the wave force of the elliptical and polygon section is smaller, but they are more sensitive to the change of wave height, and the increase is obvious. The distribution of wave force in the circular section is more uniform.

2

Dangerous phones arising from the waves during the oceanic route ship

Szelangiewicz T., Żelazny K.

New Trends in Production Engineering

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2018

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Vol. 1, Iss. 1

183--189

EN

Ocean routes are recommended for ships based on economic criteria. Under the influence of waves, during the cruise of the ship, dangerous phenomena are created, the intensity of which depends on the speed of the ship and its course in relation to the direction of the waves, the state of the sea, the size of the ship, the state of loading. Although weather services are known, waves parameters are not used to calculate the value of parameters that characterize dangerous phenomena. The article presents the most frequently analysed dangerous phenomena, how they are calculated, the criteria for their evaluation, and the results of calculations for the selected vessel.

3

Simulation of irregular waves in a numerical wave tank

Li Z-F., Shi Y. Y., Ren H. L., Li H., Ashraf M. A.

Polish Maritime Research

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2015

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S 1

21--25

EN

The time domain boundary element method was utilized to simulate the propagation of the irregular waves in a numerical wave tank. The problem was solved in a time-marching scheme, upon the irregular waves being fed through the inflow boundary, in which the theoretical solution was obtained from the wave energy spectrum. The open boundary condition was modeled by the multi transmitting formula (MTF), in which the phase velocity was calculated according to the Sommerfeld’s condition. The velocity potential and wave elevation were directly obtained by integrating the free surface condition twice, with respect to time. The accuracy of the developed numerical scheme was verified by simulating the propagation of irregular waves. The numerical results show good agreements with the analytical solutions, which prove that the proposed scheme is a promising way to the simulation of wave-body interactions.

4

Approximation of pitching motion of S-175 containership in irregular waves on the basis of ship's service parameters

Cepowski T.

Polish Maritime Research

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2006

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nr 1

22-25

EN

This paper presents approximations of pitching motion of S-175 containership in irregular waves within the full range of ship's service parameters. It continues the research described in [1] dealing with application of artificial neural networks to predict ship's motions. Reference pitch values were calculated by means of SEAWAY software based on accurate numerical methods. Approximating function was elaborated by using the artificial neural networks.