Numerical study on wave-induced hydro-elastic responses of a floating raft for aquaculture

被引:10
作者
Chu, Bei [1 ,2 ]
Chen, Yiren [1 ,2 ]
Zhang, Yao [3 ]
Zhang, Guangming [1 ,2 ]
Xiang, Xu [4 ]
Zhang, Xinshu [1 ,2 ]
机构
[1] Shanghai Jiao Tong Univ, State Key Lab Ocean Engn, Shanghai 200240, Peoples R China
[2] Collaborat Innovat Ctr Adv Ship & Deep Sea Explor, Shanghai 200240, Peoples R China
[3] Minist Nat Resources, Natl Marine Hazard Mitigat Serv, Beijing 100000, Peoples R China
[4] Norwegian Publ Rd Adm, Oslo, Norway
关键词
Hydroelastic response; Floating raft; Aquaculture; Mooring system; Extreme response; Irregular waves; DYNAMICS;
D O I
10.1016/j.oceaneng.2021.109869
中图分类号
U6 [水路运输]; P75 [海洋工程];
学科分类号
0814 ; 081505 ; 0824 ; 082401 ;
摘要
The paper presents the study on hydro-elastic responses of a floating raft with a mooring system in both regular and irregular waves. The floating raft consists of a number of buoys, plates and a mooring system, which are modeled by Morison type elements with proper coefficients, segmented line elements with stiffness and several mooring cables, respectively. The added mass coefficients of the buoys are computed by using the panel code WAMIT. Damping coefficients are obtained by CFD simulations of the forced surge/sway motions of a buoy with a free surface. Due to the nonlinear performance of the mooring system, the periods of maximum responses of the structure decrease as the wave height increases. For regular waves, the most of dangerous wave conditions are found in the wave periods 6 similar to 10 s with the incident wave angles 0 degrees similar to 20 degrees or 70 degrees similar to 90 degrees, while the floating raft is relatively safe for the incident wave angle being around 45 degrees. For irregular waves, the impacts of randomness are analyzed by using different wave seeds. Most of the results are not sensitive to the randomness of the phase angles, except for the maximum mooring tensions which show noticeable fluctuations (similar to 15%). By comparing the results of the long-crested wave and short-crested wave, it is found that the predictions of the mooring tension and the responses of the floating raft are more conservative in long-crested wave than those in short-crested wave. Besides, the impacts of different frequency ranges on the time histories of the responses are discussed. The maximum structural responses are compared with the most probable maximum (MPM) values obtained by assuming Rayleigh distribution for the responses. The most vulnerable locations of the structure are analyzed based on the maximum dynamic loads on the plates of the floating raft. When the zero-crossing period exceeds 5 s, the relatively large tensions on the plates occur in the north and south sides of the floating raft. The relatively large shear force, bending moment, normal stress, torque and shear stresses on the plates always occur in the four corners of the floating raft.
引用
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页数:27
相关论文
共 27 条
[1]   Modeling of dynamic behavior of a single-point moored submersible fish cage under currents [J].
DeCew, J. ;
Tsukrov, I. ;
Risso, A. ;
Swift, M. R. ;
Celikkol, B. .
AQUACULTURAL ENGINEERING, 2010, 43 (02) :38-45
[2]   Effect of different longline farming designs over the growth of Mytilus chilensis (Hupe, 1854) at Llico Bay, VIII Region of Bio-Bio, Chile [J].
Diaz, C. ;
Figueroa, Y. ;
Sobenes, C. .
AQUACULTURAL ENGINEERING, 2011, 45 (03) :137-145
[3]  
DNV (Det Norske Veritas), 2010, DNVRPC205
[5]  
Faltinsen O., 1993, Sea Loads on Ships and Offshore Structures, VVolume 1
[6]  
FAO, 2022, Fisheries and Aquaculture Department, FAO FishFinder Aquatic Species-Fact Sheets, Diplodus sargus, DOI [10.4060/ca9229en, DOI 10.4060/CA9229EN, 10.4060/ca9229-n, DOI 10.4060/CC0461EN]
[7]  
FAO, 2017, FISH AQ COUNTR PROF
[8]   Development of structural modeling techniques for evaluating HDPE plastic net pens used in marine aquaculture [J].
Fredriksson, David W. ;
Decew, Judson C. ;
Tsukrov, Igor .
OCEAN ENGINEERING, 2007, 34 (16) :2124-2137
[9]  
Fu SX, 2017, PROCEEDINGS OF THE ASME 36TH INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARCTIC ENGINEERING, 2017, VOL 9
[10]   Experimental investigation on hydrodynamics of floating cylinder in oscillatory and steady flows by forced oscillation test [J].
Fu, Shixiao ;
Xu, Yuwang ;
Hu, Ke ;
Zhang, Yu .
MARINE STRUCTURES, 2013, 34 :41-55