Numerical optimization of trawl energy efficiency taking into account fish distribution
Article dans une revue avec comité de lecture
This study reports on energy efficiency optimization regarding bottom trawls. Efficient fishing gear uses up only a small amount of energy per fish caught. Drag and mouth area during trawling operations affect energy efficiency. Drag causes the energy consumption and the trawl mouth area impacts the quantity of fish caught, hence an energy efficient gear has a low ratio drag on the mouth area. A novel numerical optimization technique using spatial fish distribution is presented in this work. The tool is based on a FEM mechanical model for trawls which consist mostly of netting panels sewn together. This tool is adapted to minimize an objective function namely the drag-to-mouth area ratio. This technique consists in modifying the design of all the panels of the trawl. In this paper the modifications are constant and quantified in terms of mesh number. Moreover the trawl mouth area takes into account the presence of fish within a given depth with respect to sea bottom and the value of the depth is adapted to the fish species of interest. Trawl design optimization with two uniform fish distributions at a given depth (6 m and 3 m above the sea bed) and one linear distribution at 6 m above the sea bed are compared. The application of this tool when designing a bottom trawl for research vessels leads to an energy economy ranging from 16% to 52% under certain assumptions.
Showing items related by title, author, creator and subject.
Article dans une revue avec comité de lectureKHALED, Ramez; PRIOUR, Daniel; BILLARD, Jean-Yves (Elsevier, 2013)A numerical method for optimization of the cable lengths in trawls with respect to the ratio between the estimated trawl drag and the predicted catch efficiency is developed and applied. The trawl cables of interest are ...
KGmax curves associated with second generation intact stability criteria for different types of ships Article dans une revue avec comité de lectureGRINNAERT, François; BILLARD, Jean-YVes; LAURENS, Jean-Marc (Springer Verlag (Germany), 2016)Currently, second generation intact stability criteria are being developed and evaluated by the International Maritime Organization (IMO). In this paper, we briefly present levels 1 and 2 assessment methods for the criteria ...
Experimental study of bubble sweep-down in wave and current circulating tank: Part I—Experimental set-up and observed phenomena Article dans une revue avec comité de lectureDELACROIX, Sylvain; GERMAIN, Gregory; GAURIER, Benoit; BILLARD, Jean-Yves (Elsevier, 2016)Bubble sweep-down is a significant issue for the oceanographic vessels, which affect the acoustic sur- veys. Experimental trials, carried out in the Ifremerwave and current circulating tank on a 1/30 model of the Pourquoi ...
Article dans une revue avec comité de lectureDELACROIX, Sylvain; GERMAIN, Gregory; BERGER, Laurent; BILLARD, Jean-Yves (Elsevier, 2015)Bubble sweep-down on oceanographic vessels generates acoustic perturbations.We propose in this work to characterize the sub-surface bubbles occurrence conditions from acoustic data analysis acquired during surveys in ...
Communication avec acteZHANG, Jishen; GABILLET, Céline; CLEMENT, Adrien; BILLARD, Jean-Yves (2016)To investigate the effect of intermediate sized bubble injection into a turbulent boundary layer under a strong gravity effect, we measure the velocity field of two-phase flow in a horizontal cavitation tunnel with 2D ...