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| Khaled, Ramez; Priour, Daniel; Billard, Jean-yves. |
| 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 warps, bridles, headline and footrope. The optimization algorithm applies an ordered sequential process changing one cable length at the time. It is assumed in the predictions that the catch efficiency of the trawl is proportional with the trawl mouth area. In a case study optimizing a bottom trawl used on a research vessel by applying the new method it is predicted that it would be possible to reduce the ratio between trawl drag and catch efficiency by up to 46% by optimizing the cable lengths. Thus this would enable a considerable... |
| Tipo: Text |
Palavras-chave: Bottom trawl; Modeling; Optimization; Fuel consumption; Drag; Swept area; Mouth surface; Fish distribution. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00130/24106/22857.pdf |
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| Germain, Gregory; Priour, Daniel; Vincent, Benoit; Billard, Jean-yves; Druault, Philippe; Bouhoubeiny, Elkhadim; Alexandrini, Bertrand; Le Touze, David; Khaled, Ramez; Mnassri, Ilyes. |
| Le comportement hydrodynamique des structures poreuses utilisées pour la pêche (chaluts, nasses, cages, seines) est aujourd’hui encore mal connu. Les chaluts étant responsables de la plus grosse part de la consommation de fuel en action de pêche, ce projet a pour objectif de développer un outil de conception de chalut permettant de réduire au maximum la traînée de l’engin.L’outil ainsi développé devrait permettre d’obtenir un gain de l’ordre de 20% sur la traînée d’un chalut, tout en conservant une efficacité en pêche comparable. Les développements réalisés pourront également être étendus pour étudier les différents types de structures poreuses utilisées pour la pêche et mieux appréhender le développement de dispositifs de sélectivité. |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00116/22716/20683.pdf |
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| Priour, Daniel; Khaled, Ramez. |
| Trawls energy efficiency is greatly affected by the drag, as well as by the swept area. The drag results in an increase of the energy consumption and the sweeping influences the catch. Methods of optimisation of the trawl design have been developed in order to reduce the volume of carburant per kg of caught fish and consequently the drag per swept area of the trawl. Based on a finite element method model for flexible netting structures, the tool modifies step by step a reference design. For each step the best-modified design, in terms of drag per swept area is kept. Such optimisation can lead to a decrease of the drag or an increase of the swept area. In the second case, that could lead to an increase of fishing effort. To avoid such increase, which could... |
| Tipo: Text |
Palavras-chave: Fishing; Fuel; Fishing gear; Trawl; Optimisation; Fishing effort. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00170/28151/26381.pdf |
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