The Numerical Simulation of Two-Degrees-of-Freedom Vortex-Induced Vibrations of Circular Cylinder with High Mass-Ratio

Abstract:

The two-degrees-of-freedom VIV of the circular cylinder with high mass-ratio is numerically simulated with the software ANSYS/CFX. The VIV characteristic is analyzed in the different conditions (Ur=3, 5, 6, 8, 10). When Ur is 5, 6, 8 and 10, the conclusion which is different from the cylinder with low mass-ratio can be obtained. When Ur is 3, the frequency of in-line VIV is twice of that of cross-flow VIV which is equal to the frequency ratio between drag force and lift force, and the in-line amplitude is much smaller than the cross-flow amplitude. The motion trace is the crescent. When Ur is 5 and 6, the frequency ratio between the drag force and lift force is still 2, but the main frequency of in-line VIV is mainly the same as that of cross-flow VIV and the secondary frequency of in-line VIV is equal to the frequency of the drag force. The in-line amplitude is still very small compared with the cross-flow amplitude. When Ur is up to 8 and 10, the frequency of in-line VIV is the same as the main frequency of cross-flow VIV which is close to the inherent frequency of the cylinder and is different from the frequency of drag force or lift force. But the secondary frequency of cross-flow VIV is equal to the frequency of the lift force. The amplitude ratio of the VIV between in-line and cross-flow direction is about 0.5. When Ur is 5, 6, 8 and 10, the motion trace is mainly the oval.

• Periodical: Applied Mechanics and Materials (Volumes 284-287)
• Pages: 557-561
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.284-287.557
• Online since: January 2013
• Authors: Jie Li Fan, Wei Ping Huang
• Keywords: Computational Fluid Dynamics (CFD), Cross-Flow VIV, High Mass-Ratio, In-Line VIV, Vortex-Induced Vibration (VIV)

References

[1] Saprkapa T. Journal of Applied Mechanics, (1979), 46: 241-258.

[2] Bearman P W. Annual Review of Fluid Mechanics, (1984), 16: 195-222.

[3] Parkinson G V. Progress in Aerospace Science, (1989), 26: 169-224.

[4] Govardhan R and Williamson C H K. Journal of Fluid Mechanics, (2000), 420: 85-130.

[5] Al-Jamal H and Dalton C. Journal of Fluids and Structures, (2004), 19: 73-92.

[6] Willden R H J and Graham J M R. Journal of Fluids and Structures, (2001), 15: 659-669.

[7] Willden R H J and Graham J M R. European Journal of Mechanics B/Fluids, (2004), 23: 209-218.

[8] Khalak A and Williamson C H K. Journal of Fluids and Structures, (1999), 13: 813-851.

[9] Vandiver J K. Journal of Fluids and Structures, (1987), 1: 381-399.

[10] Moe G and Wu Z J. ASME Journal of Offshore Mechanics and Arctic Engineering, (1990), 112: 297-303.