AN ANALYSIS OF THE DYNAMICS OF TOWING CABLES

The linearized dynamic and kinematic equations for the three-dimensional motions of a faired towing cable in a uniform flow are formulated with special attention to the hydrodynamic forces. Sinusoidal kinematic boundary conditions are applied to the cable at the tow point and simple dynamic boundary conditions are applied to the towed body. Analysis is done in the frequency domain. The resulting equations are solved numerically. The method is shown to be applicable over a range of practical cases. A computational difficulty involving the interaction of growing solutions with round-off error is identified. Demonstrably the difficulty may be put off by increasingly precise computation. The effect of important physical parameters of the problem on the motions transmitted from the tow point down the cable to the towed body are evaluated. Results are understood in terms of the natural frequencies of the oscillatory modes which combine to produce the cable dynamics. A design principle is established for minimizing towed body motions by partially decoupling the tow point from the towed body using moderately extensible cables.

• Supplemental Notes:
  • Doctor of Science Thesis.
• Corporate Authors:

  Massachusetts Institute of Technology

  Department of Ocean Engineering, 77 Massachusetts Avenue
  Cambridge, MA  United States  02139
• Authors:
  • Firebaugh, M S
• Publication Date: 1972-1

Subject/Index Terms

• TRT Terms: Cables; Dynamics; Towing devices
• Old TRIS Terms: Cable dynamics; Towed body systems; Towing cables
• Subject Areas: Design; Marine Transportation;

Filing Info

• Accession Number: 00034666
• Record Type: Publication
• Source Agency: Massachusetts Institute of Technology
• Files: TRIS
• Created Date: Sep 27 1972 12:00AM