Comparison between physical model testing and numerical simulation using two-way fluid-structure interaction approach of new trawl design for coastal bottom trawl net

Thierry, Nyatchouba Nsangue Bruno; Tang, Hao; Xu, Liuxiong; Hu, Fuxiang; Dong, Shuchuang; Achille, Njomoue Pandong; Zou, Baiqiang

doi:10.1016/j.oceaneng.2021.109112

Cited by 7 publications

(3 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to the research of O’Neill et al 11 regarding the analysis of the effect of catch size on the codend drag, and that of Druault and Germain 13 on the analysis of hydrodynamics of the moving trawl codend and its fluttering motions, the presence of the catch inside the trawl net results in a larger codend volume and blockage of the meshes, which limits the flow passage through the trawl structure and generates a greater transverse drag pressure on the trawl net. This transversal drag pressure produced the unsteady motions on the three axes causes a strong reduction in the flow velocities, which in turn cause a flow disturbance, creating the vortex shedding inside the trawl near the catches and around the trawl codend 6 , 12 , 13 , 47 .…”

Section: Discussionmentioning

confidence: 99%

Turbulent flow interacting with flexible trawl net structure including simulation catch in flume tank

Thierry

Tang

Liu

et al. 2023

Sci Rep

Self Cite

View full text Add to dashboard Cite

The interaction between fluid and the midwater trawl with stocked catches is extremely complex, but essential to improve the understanding of the drag force acting on the trawl, the behavior of the fishing structure during a trawling process, and to predict its selectivity process. The present study assesses the turbulent characteristics inside and around the midwater trawls with catch and without catch linked to its fluttering motion. The analysis is based on three-dimensional electromagnetic current velocity meter measurements performed in the multiple points inside and outside different parts of a 1/35 scaled midwater trawl model with the aim of access the main turbulent flow structure inside and around the gear. Time-averaged normalized flow velocity fields and turbulent flow parameters were analyzed from the measured flow data. Furthermore, Fourier analysis was conducted by watching the time–frequency Power spectrum content of instantaneous flow velocities fields, the fluttering trawl motions, turbulent kinetic energy, and momentum flux. Based on successive analyzes of mean flow characteristics and turbulent flow parameters, it has been demonstrated that the presence of catch inside the trawl net impacts the evolution of unsteady turbulent flow by creating large trawl fluttering motions that strongly affect the flow passage. The results showed that the time-averaged normalized streamwise and transverse flow velocities inside and around the trawl net with catch were 12.41% lower compared with that obtained inside and around the trawl without catch. The turbulent length scale and turbulent Reynolds number obtained in the different part of the trawl net with catch were about 33.05% greater than those obtained on the trawl net without catch, confirming that the unsteady turbulent flow developing inside and around the midwater trawl is influence by the catch and liner. It is observed that the motions of both the trawl without catch and the trawl with catch are mainly of a low-frequency activity and another component related to unsteady turbulent flow street. A complex fluid–structure interaction is then demonstrated where the fluttering motions of the trawl net affect the fluid flow inside and around trawl net, the fluid force, turbulent pattern, and simultaneously, the periodic unsteady turbulent flow influence the trawl motions.

show abstract

Section: Discussionmentioning

confidence: 99%

Turbulent flow interacting with flexible trawl net structure including simulation catch in flume tank

Thierry

Tang

Liu

et al. 2023

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…Guan et al [22] investigated the hydrodynamic performance of a new type of bottom trawl using numerical simulation and physical modeling methods. According to the literature, numerical simulation has become an important tool to study the hydrodynamic performance of the trawl system [23,24]. Mai The Vu and Hyeung-Sik Choi [25][26][27][28][29][30] provided valuable theories for establishing the mathematical model of dynamic coupled analysis of cable and trawl ships.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Response of Deep-Sea Trawl System during Towing Process

Zhang

Zhao

Zhu

et al. 2023

JMSE

View full text Add to dashboard Cite

The trawl system plays an irreplaceable role in deep-sea fishing. In the towing process of the trawl system, many complex mechanical phenomena occurs, so it is necessary to analyze the dynamic response of the deep-sea trawl system during the towing process. In this paper, an equivalent mathematical model for predicating the movement of the ocean trawl system is established based on the equivalent net theory. In the proposed method, the lumped mass method is used to simulate the towed cable and some lines with hydrodynamic characteristics are used to simulate the fishing net. The effects of towing speeds on the dynamic characteristics of a rigid truss trawl system and a flexible trawl system during straight-line towing and rotation towing are studied. The results show that it is possible to simulate trawl motion, and the trawling process is well-presented using this equivalent mathematical model. The disadvantage of this method is also obvious, that is, it cannot simulate trawls with a large number of meshes because the proliferation of mesh numbers can lead to difficult computational convergence. The results also demonstrate that during straight-line towing, the higher the speed, the greater the tension of the cable. Due to the rigid truss, the shape of the rigid truss trawl under different towing speeds is not much different, while the shape of the flexible trawl system changes greatly. During rotating towing, the tension of the cable changes abruptly in the initial stage, and then fluctuates periodically in the time domain. With the increase of towing speed, the overall outward floating distance of the trawl increases gradually. This study has a certain reference and guiding role for deep-sea fishing operations.

show abstract

“…They found that the vertical distributions of flow parameters reveal the diversity of flow characteristics in the water depth direction influenced by the free surface and the outer part of the turbulence boundary layer (TBL) from the channel bottom. Thierry et al [23] (2021) Used Numerical modeling based on fluid-structure interaction in two-way coupling to identify the turbulent flow that develops around different parts of the bottom trawl. Wang et al [24] (2023) numerically analyses the effects of inclination angles on local time-averaged and instantaneous flow fields, velocity reductions, and force coefficients and found that the inclination angles have dominant effects on the time-averaged velocity magnitudes around the net meshes and the hydrodynamic characteristic of netting.…”

Section: Introductionmentioning

confidence: 99%

Flow Field Pattern and Hydrodynamic Characteristics of a Grid Device Made with Various Grid Bar Spacings at Different Inclination Angles

Zhang,

Tang,

Thierry

et al. 2023

JMSE

Self Cite

View full text Add to dashboard Cite

The grid is a crucial component in constructing grid-type bycatch reduction devices. The grid’s structural characteristics and orientation significantly impact the hydrodynamic characteristics and efficacy of the separation device. Therefore, it is essential to thoroughly understand the grid device’s hydrodynamic characteristics and flow field to optimize its structure. Thus, this study used CFD numerical simulation and flume tank experiments to investigate the effects of inclination grid angles and grid bar spacing on hydrodynamic forces and flow fields around a circular grid. The results indicated that the hydrodynamic forces acting on the circular grid increased with higher flow velocity and inclination grid angle, decreasing with smaller grid bar spacing. Flow velocity acceleration zones were observed at the upper and lower ends of the grid and between the grid bars. Additionally, upwelling and vortices were present at the back of the grid. It was found that an increase in the inclination grid angle accelerated the vortex and wake effects.

show abstract

Comparison between physical model testing and numerical simulation using two-way fluid-structure interaction approach of new trawl design for coastal bottom trawl net

Cited by 7 publications

References 47 publications

Turbulent flow interacting with flexible trawl net structure including simulation catch in flume tank

Turbulent flow interacting with flexible trawl net structure including simulation catch in flume tank

Dynamic Response of Deep-Sea Trawl System during Towing Process

Flow Field Pattern and Hydrodynamic Characteristics of a Grid Device Made with Various Grid Bar Spacings at Different Inclination Angles

Contact Info

Product

Resources

About