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Wyszukujesz frazę "irregular waves" wg kryterium: Temat


Wyświetlanie 1-6 z 6
Tytuł:
Experiment on pressure characteristics of submerged floating tunnel with different section types under wave condition
Autorzy:
Li, Q.
Jiang, S.
Chen, X.
Powiązania:
https://bibliotekanauki.pl/articles/260098.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
submerged floating tunnel
section type
irregular waves
pressure characteristics
physical test
Opis:
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.
Źródło:
Polish Maritime Research; 2018, S 3; 54-60
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of the seakeeping of a military trimaran hull by a novel overset mesh method in regular and irregular waves
Autorzy:
Ghadimi, Parviz
Karami, Saeid
Nazemian, Amin
Powiązania:
https://bibliotekanauki.pl/articles/1818907.pdf
Data publikacji:
2021
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
trimaran
hydrodynamic performance
seakeeping
overset mesh
numerical simulation
regular and irregular waves
Opis:
The hydrodynamic performance of trimaran hulls has been previously investigated for optimum performance in calm water, but there is still a limited understanding of its motion response; therefore, a CFD-based numerical approach was developed and applied on a trimaran hull in the presence of regular and irregular waves. To validate the CFD method, a comparison was conducted using both experimental and 3D panel method data. In this study, two different turbulence models were surveyed, and the SST Menter k-Omega (k-ω) turbulence model was shown to be a more accurate model than the realizable k-Epsilon (k-ε) model. The different features of the proposed numerical model include the implementation of an overset mesh method, unique mesh plan refinement, and wave-damping region. The discrepancy between the experimental data and the results of other seakeeping calculation methods have always been problematic, especially for low-speed strip theory and 3D panel methods, but good consistency was observed between the proposed CFD model and experimental data. Unlike potential-based or conformal mapping seakeeping analysis methods, the effect of nonlinear waves, hull shape above the waterline, and other ship dynamic phenomena were considered in this CFD application. The proposed CFD method reduces the simulation time and computational efforts for ship motion calculations.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2021, 65 (137); 38-50
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of irregular waves in a numerical wave tank
Autorzy:
Li, Z-F.
Shi, Y. Y.
Ren, H. L.
Li, H.
Ashraf, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/260392.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
open boundary condition
multi transmitting formula
irregular waves
boundary element method
numerical wave tank
Opis:
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.
Źródło:
Polish Maritime Research; 2015, S 1; 21-25
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dangerous phones arising from the waves during the oceanic route ship
Autorzy:
Szelangiewicz, Tadeusz
Żelazny, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/27315878.pdf
Data publikacji:
2018
Wydawca:
STE GROUP
Tematy:
forecasting of shipping routes
irregular waves
dangerous phenomena
sailing at the waves
prognozowanie tras żeglugowych
fale nieregularne
niebezpieczne zjawiska
żeglowanie na falach
Opis:
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.
Źródło:
New Trends in Production Engineering; 2018, 1, 1; 183-189
2545-2843
Pojawia się w:
New Trends in Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Approximation of pitching motion of S-175 containership in irregular waves on the basis of ships service parameters
Autorzy:
Cepowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/259629.pdf
Data publikacji:
2006
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
aproksymacja
właściwości morskie
kiwania
parametry ruchu statków
sztuczne sieci neuronowe
fale nieregularne
seakeeping qualities
pitching
artificial neural networks
approximation
ship service parameters
irregular waves
Opis:
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.
Źródło:
Polish Maritime Research; 2006, 1; 22-25
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of waves on dangerous stability of vessels on the oceanic route
Autorzy:
Szelangiewicz, T.
Żelazny, K.
Powiązania:
https://bibliotekanauki.pl/articles/27315945.pdf
Data publikacji:
2018
Wydawca:
STE GROUP
Tematy:
nieregularna fala
toczenie się statku
stabilność na belce i podążanie za falami
zmienny moment prostujący
irregular wave
rolling of a vessel
stability on beam and following waves
variable righting moment
Opis:
Stability is one of the most important properties of the ship. The greatest influence on stability and thus on the possibility of loss of stability have the rolling of the ship on the wave. Mathematical models describing rolling on wave are complicated, and their solution, especially in the irregular wave, is only possible with numerical methods in the time domain. Large rolling, until the ship capsize, formation not only on the beam wave, but also on the following wave. Various models describing rolling (linear and nonlinear, regular and irregular wave, and constant or variable restoring moment) are presented. The predicted level hazard of stability of the ship depends on the direction of the wave and the cases where the level of hazard will be greatest.
Źródło:
New Trends in Production Engineering; 2018, 1, 1; 469-477
2545-2843
Pojawia się w:
New Trends in Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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