Experimental study of current forces and deformations on a half ellipsoidal closed flexible fish cage

Strand, Ida Marlen; Sørensen, Asgeir J.; Volent, Zsolt; Lader, Pål

doi:10.1016/j.jfluidstructs.2016.05.011

Cited by 17 publications

(6 citation statements)

References 11 publications

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“…As shown in 2020) and Strand et al (2016). They studied the volume reduction and structural safety of the flexible fish cage in waves and tidal currents, ensuring that fish cages could meet the design requirements for different environmental conditions.…”

Section: Hydrodynamic Characteristicsmentioning

confidence: 99%

Review of Structure Types and New Development Prospects of Artificial Reefs in China

et al. 2022

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Artificial reefs are beneficial to restore fishery resources and increase fishery production. Meanwhile, they play a significant role in improving ocean ecology and accelerating the evolution of fishery industries. Since they are generally affected by currents, waves, and other hydrological factors, the flow field around artificial reefs and their stabilities have become a research hotspot in recent years. Research on artificial reefs is a systematic process consisting of four aspects: Firstly, the significance, the definition, the mechanism, and the present research progress were introduced for artificial reefs in detail. Secondly, the development trend of the sit-bottom artificial reef and that of the floating artificial reef were summarized, respectively. Thirdly, it was found that the combination of traditional artificial reefs and emerging ocean engineering has a great development potential in practical engineering. Finally, the existing problems related to the hydrodynamic characteristics of the artificial reefs in China were summarized, and the prospects of artificial reefs were proposed. The purpose of this study is to provide a scientific reference for the ecological and sustainable development of the large-scale construction of artificial reefs in the ocean.

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Section: Hydrodynamic Characteristicsmentioning

confidence: 99%

Review of Structure Types and New Development Prospects of Artificial Reefs in China

et al. 2022

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“…Among others, coupled ship motions and sloshing analysis have been carried out for ships, using either Computational Fluid Dynamic (CFD) [6] or the multimodal approach [7] for sloshing. For the flexible floating cylindrical cage, the responses of the cage in waves have been studied by [8], followed by experimental studies on the wave induced responses [9], where the drag forces on a half ellipsoidal closed flexible fish cage were modeled. Kristiansen et al [10] carried out model tests of a closed fish cage in regular waves, and compared with linear numerical results in the frequency domain.…”

Section: Figure 1: Rigid Cylindrical Closed Cage Frommentioning

confidence: 99%

“…, (9) where β j (t) is also the generalized coordinate for expanding the free surface elevation as a series in terms of the natural sloshing modes.…”

Section: Nonlinear Multimodal Equations For Circular Cylindermentioning

confidence: 99%

Coupled Motion and Sloshing Analysis of a Rigid Cylindrical Closed Fish Cage in Regular Waves

Tan

Shao

Read

2019

Volume 6: Ocean Space Utilization

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In this paper, a coupled numerical model in the time domain has been developed to study the interaction between interior liquid sloshing and the motion of a cylindrical closed fish cage when the cage is exposed to regular waves. The single-dominant nonlinear multimodal theory for sloshing in a cylindrical cage presented in [1] was implemented to simulate the liquid responses in the cage. A time-domain simulator based on the Cummins formulation of the equations of motion [2] is used to solve for the cage motion, while WAMIT is used to provide all required frequency-domain hydrodynamic coefficients for the external diffraction/radiation problems. Details of the coupling between cage motion and sloshing will be presented. The coupled solver is verified against the linear frequency-domain solution from WAMIT for the very small wave steepness, where linear theory is valid. The results show that the sloshing effect is a vital factor in the coupling process, which means that the liquid in the closed cage cannot be treated as a solid mass. This is particularly true close to the resonant frequencies of the liquid in the tank. Furthermore, the importance of nonlinearity due to sloshing responses is investigated by applying incident waves with different steepness. When the cage is exposed to regular waves, if certain criteria are met, nonlinear swirling waves are observed in the closed cage. The nonlinear swirling waves are due to the interactions between different sloshing modes, which can only be explained by a proper nonlinear theory, such as the multimodal theory applied in this study. The influence of the swirling waves on the cage motions will also be discussed in the paper. How this effect will impact the design of a closed fish cage and its mooring system can only be answered by studying the cage responses in irregular waves, which is the subject of ongoing research.

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“…The reason why the main body of the reef is very similar to the structure of aquaculture cage includes two aspects: (1) the buoyancy system of floating reef includes float tube and float ball, which based on permutation and combination; (2) the reef's body is woven by mooring rope and fishing net. (Hou et al [7]; Huang et al [8]; Bai et al [9]; Zhao et al [10]; Gui et al [11]; Moe-Føre et al [12]; Strand et al [13]) have long been committed to the research of the structure type of net cage, the movement of net cage's floating frame, the mode of mooring, and the change of net cage's volume. They solved the problem of the size reduction and structural safety of the flexible structure of net cage under the action of waves and tidal currents, and ensured that net cage could meet the design requirements in different marine environments.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation Study on Environment-Friendly Floating Reef in Offshore Ecological Belt under Wave Action

Pan

Tong

Zhou

et al. 2021

Water

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An artificial floating reef is an important part of the coastal ecological corridor. The large-scale construction of floating reefs by optimizing mooring methods can effectively improve the ecological effects of coastal projects. The artificial floating reef belongs to coastal engineering, and wave resistance is fundamental to its structural design. In this paper, the method for processing coupling forces and motion, the method for judging the floating reef out of water surface, and the method for correcting velocity and acceleration of water mass points are elaborated in detail by using the finite element method and lumped-mass mooring model. By comparing and analyzing the results of physical experiment and numerical simulation, the correctness of the numerical model is verified. Finally, the diachronic variation of pitching angle of floating reef, the tension of the mooring rope, and the total tension of the fixed points of the fishing net were analyzed by the dynamic response numerical mode with a new type of mooring. The purpose of the current study was to provide a basis for the optimization of structure shape, the matching of floating body, and the counterweight of artificial floating reef.

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Experimental study of current forces and deformations on a half ellipsoidal closed flexible fish cage

Cited by 17 publications

References 11 publications

Review of Structure Types and New Development Prospects of Artificial Reefs in China

Review of Structure Types and New Development Prospects of Artificial Reefs in China

Coupled Motion and Sloshing Analysis of a Rigid Cylindrical Closed Fish Cage in Regular Waves

Numerical Simulation Study on Environment-Friendly Floating Reef in Offshore Ecological Belt under Wave Action

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