Flume tank evaluation of the hydrodynamic lift and drag of helix ropes compared to conventional ropes used in midwater trawls

OCEAN ENGINEERING

卷:195

Article

Kebede, Gebremeskel Eshetu¹  Winger, Paul D.¹  DeLouche, Harold¹  Legge, George¹  Cheng, Zhaohai¹  Kelly, David²  Einarsson, Haraldur³ 

[1] Mem Univ, Fisheries & Marine Inst, Ctr Sustainable Aquat Resources, 155 Ridge Rd, St John, NF A1C 5R3, Canada

[2] Hampidjan Canada Ltd, 527 Concept Bay Hwy, Spaniards Bay, NF A0A 3X0, Canada

[3] Marine & Freshwater Res Inst, Skulagata 4, IS-101 Reykjavik, Iceland

关键词: Helix;    Drag;    Lift;    Drag coefficient;    Lift coefficient;    Attack angle;    Reynolds number;   

DOI  :  10.1016/j.oceaneng.2019.106674

来源: Elsevier

【 摘 要 】

The hydrodynamic properties of ropes can significantly affect the underwater performance of midwater trawls, including their geometry, drag, fuel consumption, and rate of gear setting and hauling activities. In this study, we investigate the hydrodynamic properties of helix ropes compared to conventional polyethylene (PE) and nylon (PA) ropes. Flume tank tests were conducted using 17 different braided and twisted ropes of varying diameter (6 mm, 8 mm, 9 mm, and 14 mm). Samples of each rope type were subjected to a series of water velocities (0.5 m/s, 0.7 m/s, and 0.9 m/s) and angles of attack (0 degrees, 12 degrees, 20 degrees, 45 degrees, 61 degrees, and 90 degrees) in order to measure drag and lift forces. To understand how hydrodynamic coefficients vary with increasing Reynolds number (Re), we also evaluated a wider range of water velocities (0.3 m/s to 0.9 m/s) for 14 mm ropes. Our results showed that, when compared to conventional ropes of the same diameter, helix ropes produced increased lift force (L), verifying their description as self-spreading ropes. To our knowledge, these findings represent the first known evidence of its kind published in scientific literature with direct application to midwater trawling operations.

【 授权许可】

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