Differential Equations Governing the Geometry of a Diamond Mesh Cod-end of a Trawl Net

[+] Author and Article Information
F. G. O’Neill

SOAEFD Marine Laboratory, P.O. Box 101, Victoria Road, Aberdeen AB11 9DB, Scotland

J. Appl. Mech 64(1), 7-14 (Mar 01, 1997) (8 pages) doi:10.1115/1.2787297 History: Received July 01, 1995; Revised August 01, 1996; Online October 25, 2007


A new surface, made up of an infinite number of infinitesimal meshes, is defined to approximate the cod-end. The force balance on a mesh element of this surface is considered in the limit as the mesh size tends to zero and the differential equations governing the geometry of a diamond meshed cod-end of circular cross section are derived in cartesian coordinates. The parametric form of the equations in terms of a , the distance along the cod-end profile, is then deduced and some special cases examined. In particular the case of a partially filled cod-end hanging under gravity is investigated and experimental measurements are compared with numerically obtained theoretical predictions. The numerical results are shown to provide a good description of the cod-end geometry except where the cod-end diameter is at its narrowest where there is a systematic departure of the predicted values from those measured. It is demonstrated that a probable explanation of this discrepancy is the assumption that the knots are simple points of intersection rather than finite well-defined structures.

Copyright © 1997 by The American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.





Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In