FLOW-INDUCED TORSIONAL MOMENT AND VORTEX SUPPRESSION FOR A CIRCULAR CYLINDER WITH CABLES

Tests were carried out to find a means of alleviating vortex- shedding-induced vibration of a deep-ocean mining pipe and to measure flow-induced torsional moment of the pipe. Test measurements included mean and root-squared values of lift, drag, torsional moment, and frequency and relative intensity of the shed vortices. Vortex-shedding characteristics were further investigated through flow visualization techniques. Five pipe configurations were tested at Reynolds number, Re = 5x104 ~ 2.5x105, for their effectiveness in reducing vortex-shedding intensity. The two most effective configurations were a pipe, straked with electro-mechanical power cables arranged in helical form with a pitch angle of 580, and a pipe with a perforated shroud. These two configurations generated the least vortex-shedding intensity, had minimum unsteady lift, and the smallest increment in drag compared to a bare pipe. Tests of a straight-down power-cable configuration (cable parallel to pipe axis) showed significant drag and lift increase, plus larger flow-induced torsional moment and, a mean nonzero lift.

• Supplemental Notes:
  • ISOPE 94, 4th Intl Offshore & Polar Engng Conf; 10-15 April 1994; Osaka, Japan. Sponsored by ISOPE, USA et al. Procs. Pubs by ISOPE, ISBN 1-880653-13-3. Vol III, p 447 [13 p, 18 ref, 21 fig]
• Authors:
  • Chung, J S
  • Whitney, A K
• Publication Date: 1994

Language

• English

Subject/Index Terms

• TRT Terms: Cylindrical bodies; Flow; Torsion; Vibration; Vortex shedding
• Old TRIS Terms: Flow induced vibration; Torsional vibration
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00709597
• Record Type: Publication
• Source Agency: British Maritime Technology
• Files: TRIS
• Created Date: Aug 14 1995 12:00AM