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Drag characterisation of prawn-trawl bodies


Balash, C and Sterling, D and Binns, J and Thomas, G and Bose, N, Drag characterisation of prawn-trawl bodies, Ocean Engineering, 113 pp. 18-23. ISSN 0029-8018 (2016) [Refereed Article]

Copyright Statement

Crown Copyright 2015 Published by Elsevier Ltd. All rights reserved.

DOI: doi:10.1016/j.oceaneng.2015.12.034


The drag of a prawn-trawl body is characterised by five design and three operational variables. The design variables comprise headline length, steepness of trawl side cut, width-to-depth mesh ratio of the trawl mouth (gape), vertical wing-end mesh count, and netting solidity; all of which effectively determine the planar twine-area of the trawl. The operational variables include towing velocity, horizontal spread, and vertical opening (headline height) - these determine the extent that the netting is exposed to relative water movement. The individual drag effects of the above variables (except for headline length, gape, and netting solidity) were systematically examined in a flume tank with prawn-trawl models built with low-stiffness full-scale netting; and the existing literature was consulted on the drag effects of gape, while drag was assumed to be proportional to twine diameter, mesh size−1 and headline length2. The developed equations in non-dimensional forms provide the basis for a drag-prediction model for a prawn trawl of any size, construction and operating conditions. Comparisons with previously published prediction equations showed considerable disagreement in some aspects, and suggest that using stiff, full-scale netting in past model experiments have produced significant model-to-full-scale prediction errors owing to the poor equivalence of twine bending-stiffness-to-netting-tension ratio.

Item Details

Item Type:Refereed Article
Keywords:prawn trawl drag, netting drag, trawl body taper, trawl horizontal spread, trawl gape, trawl vertical opening, wing-end mesh count
Research Division:Engineering
Research Group:Maritime engineering
Research Field:Ocean engineering
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - wild caught
Objective Field:Wild caught prawns
UTAS Author:Balash, C (Dr Cheslav Balash)
UTAS Author:Binns, J (Professor Jonathan Binns)
UTAS Author:Bose, N (Professor Neil Bose)
ID Code:106374
Year Published:2016
Web of Science® Times Cited:4
Deposited By:NC Maritime Engineering and Hydrodynamics
Deposited On:2016-02-09
Last Modified:2018-03-29

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