MEASUREMENTS OF THE RESPONSE OF BLUFF CYLINDERS TO FLOW INDUCED VORTEX SHEDDING

The prediction and measurement of vortex-excited vibrations and associated fluid forces are important in such ocean engineering applications as the determination of the flow-induced lift and drag forces on sea floor pipelines and structural members, tow and mooring cables, and suspended pipelines which must be known in order to implement proper design procedures and to prevent costly failures. This paper discusses a study wherein measurements were made of the response characteristics and flow about circular cylinders that were mounted on springs in a wind tunnel. Free stream Reynolds numbers for two cylindrical models ranged respectively from 350 to 550 and from 550 to 900. The measured vibration frequencies, amplitudes, and phase angles are compared with predictions made with an heuristic wake oscillator model for the vortex-excited vibrations. Steady drag measurements were made and show that the drag coefficient increases by as much as 75 percent at the maximum vibration amplitude from the measured stationary cylinder value. Lift amplification and energy transfer from the flow during resonance are compared over the range of the experiments. Energy determinations made from the measured response and damping data are in good agreement with the results of the theory. The agreement between theory and experiment indicated that further development of the wake oscillator model is warranted.

• Supplemental Notes:
  • Presented at the 1973 Offshore Technology Conference, Houston, Texas, April 30-May 2, 1973.
• Corporate Authors:

  Offshore Technology Conference

  6200 North Central Expressway
  Dallas, TX  United States  45206
• Authors:
  • Griffin, O M
  • Skop, R A
  • Koopman, G H
• Conference:
  • Presented at the 1973 Offshore Technology Conference, Houston, Texas, April 30-May 2, 1973.
• Publication Date: 1973-4

Media Info

• Features: References;
• Pagination: p. 767-778
• Serial:
  • Volume: 1

Subject/Index Terms

• TRT Terms: Cables; Dynamics; Flow; Underwater pipelines; Vibration; Vortex shedding
• Old TRIS Terms: Cable dynamics; Flow induced vibration
• Subject Areas: Design; Marine Transportation; Terminals and Facilities;

Filing Info

• Accession Number: 00054198
• Record Type: Publication
• Source Agency: National Maritime Research Center, Galveston
• Report/Paper Numbers: OTC No. 1814
• Files: TRIS
• Created Date: May 7 1974 12:00AM