Dynamic Simulation of a Midwater Trawl System's Behavior

Cha, Bong-Jin; Lee, Chun‐Woo

doi:10.2331/fishsci.68.sup2_1865

Cited by 21 publications

(3 citation statements)

References 5 publications

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“…Johansen et al [3] proposed the use of horizontal motion in trawl systems. Cha and Lee [4] performed dynamic simulations of a midwater trawling system. Reite et al [5,6] installed a brake on a net plate to control the trawling depth and performed sea trials to verify the effectiveness of the system.…”

Section: Introductionmentioning

confidence: 99%

Study on the Dynamic Response of Deep-Sea Trawlers in Sea Trials

Xie

Cai

et al. 2023

Polish Maritime Research

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The increasing use of automation in fishing vessels has improved trawling efficiency while directly affecting the fishing capacity and cost of fishing vessels. Among the various influencing factors, warp tension and warp length can be varied to automatically balance the retraction and release of warp control. We combined the two parameters and independently designed and developed the key equipment for fishing vessels—the warp dynamometer and meter counter—and control software. The accuracy of the warp tension and length measurements was improved. The designed equipment was applied to sea trials under different working conditions, and the test data records were exported. Next, filtered time-domain graphs of the required parameters were plotted through complex Fourier transform, first-order low-pass filtering, and inverse Fourier transform. The results of data processing using various parameters were compared and analysed to determine the variation trends of the parameters and verify the effects of their balance control. The results indicated that using an automatic balance control system that combines warp tension and warp length can be effective for the fishing operation of offshore double-deck trawlers. In addition, first-order low-pass filtering can be used to filter complex warp tension data. This study also determined the relationship between warp tension and experimental parameters such as warp length and ship speed during the release of control. After the balance control of warp tension and warp length, the net mouth area increased by 30.7% and 36.5%, respectively, and the fishing efficiency of the vessel improved considerably.

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Section: Introductionmentioning

confidence: 99%

Study on the Dynamic Response of Deep-Sea Trawlers in Sea Trials

Xie

Cai

et al. 2023

Polish Maritime Research

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“…With the contributions of considerable researchers working at SINTEF Ocean (Endresen et al, 2013(Endresen et al, , 2014Reite et al, 2014;Skjong et al, 2021;Su et al, 2021Su et al, , 2019Endresen and Klebert, 2020), the computer program FhSim was successfully developed with considerable verifications and applied to various applications, such as fish cages in rough seas, trawl net system and aquaculture operation. Lee (2002) and Cha and Lee (2002) developed a numerical tool for fishing gears and later applied it to fish cage analysis (Lee et al, 2008;Lee et al, 2015;Park et al, 2021). This numerical tool turned into commercial software, SimuTrawl, SimuPurse and SimuLine, under the company MPSL.…”

Section: Introductionmentioning

confidence: 99%

“…Bessonneau and Marichal (1998) proposed a method using the massspring model to study the dynamics of submerged nets with applications to trawl nets Lader et al (2001). developed a simple 2D model using the mass-spring model to analyze the dynamic response of net panels; andLader et al (2003) extended the 2D model to 3D model with an application to the dynamic analysis of a fish cage Cha and Lee (2002). andLee (2002) developed a mass-spring model for the dynamic analysis of midwater trawl, andLee et al (2008) later applied the model to the dynamic simulation of a fish cage under the action of currents and waves Takagi et al (2004),Huang et al (2006).…”

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confidence: 99%

Development of Advanced Numerical Tools for Dynamic Analysis of Aquaculture Structures

Cheng¹

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Numerical methods to accurately predict dynamic responses of marine aquaculture structures are essential in the engineering design process, because these structures can be subjected to large wave and current loads in the ocean environment, which causes complex structural motion and deformation. However, only a few numerical programs for the dynamic analysis of aquaculture structures can be accessed by the public without permission. In order to meet the high demand for a ready-for-use program, a numerical module for an open-source Finite Element Analysis (FEA) program, Code_Aster, is developed in this PhD study. This numerical module includes various wave models (e.g., Airy waves, Stokes 2nd order waves and irregular waves) and hydrodynamic force models (e.g., Morison model, Screen model and flow velocity reduction due to wake effects). Moreover, a coupling algorithm to handle the wake effects of thin, flexible and highly permeable structures with complex geometries is also implemented to solve the complex fluid-structure interaction (FSI) problem in marine aquaculture engineering. The accuracy of structural response prediction can be improved using the coupling algorithm with the open-source Computational Fluid Dynamics (CFD) solver, OpenFOAM, which can solve the complex flow field around the structures. Detailed verifications and validations are firstly conducted with considerations of different net solidities, inflow angles, incoming current velocities and net dimensions. Subsequently, the newly developed numerical module is applied to study dynamic responses of traditional fish cages, grid moored fish farms and a large semi-submersible aquaculture structure for practical engineering design and optimization purposes. The structural responses of traditional fish cages with different design parameters (including circumferences of floating collar, depths of net bag, submerged weights) are comprehensively analyzed under pure current conditions. Based on the parametric analysis with a large number of numerical simulations, regression functions for the most concerning aspects are provided for engineering usages in the design process. These regression functions can save considerable time for experiments and numerical simulations in the design of traditional fish cages. The structural responses of grid moored fish farms are analyzed with respect to combinations of mooring line breakages and current directions. Based on the numerical results, suggestions to improve the design of the mooring system are given. It is also recommended to monitor the positions of buoys during in-situ operations. When one of the mooring line breaks, the maximum tension increment in the mooring system can be estimated based on the displacement of the buoys. This estimation can help the farmer to decide whether the damaged mooring line should be repaired immediately. The global responses of a semi-submersible offshore aquaculture structure are investigated under irregular waves and current conditions which correspond to a return period of 50 years. The numerical model shows a reasonable agreement with published experimental results and demonstrates that the newly developed numerical module can be applied to the dynamic analysis of offshore aquaculture structures.

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Application of numerical simulation for analysis of sinking characteristics of purse seine

Zhou

Zhang

et al. 2014

J. Ocean Univ. China

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Dynamic Simulation of a Midwater Trawl System's Behavior

Cited by 21 publications

References 5 publications

Study on the Dynamic Response of Deep-Sea Trawlers in Sea Trials

Study on the Dynamic Response of Deep-Sea Trawlers in Sea Trials

Development of Advanced Numerical Tools for Dynamic Analysis of Aquaculture Structures

Application of numerical simulation for analysis of sinking characteristics of purse seine

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