Hydrodynamics of the Semi-Immersed Cylinder by Forced Oscillation Model Testing
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In this paper, the hydrodynamic coefficients of a horizontal semi-immersed cylinder in steady current and oscillatory flow combining with constant current are obtained via forced oscillation experiments in a towing tank. Three nondimensional parameters (Re, KC and Fr) are introduced to investigate their effects on the hydrodynamic coefficients. The experimental results show that overtopping is evident and dominates when the Reynolds number exceeds 5×105 in the experiment. Under steady current condition, overtopping increases the drag coefficient significantly at high Reynolds numbers. Under oscillatory flow with constant current condition, the added mass coefficient can even reach a maximum value about 3.5 due to overtopping while the influence of overtopping on the drag coefficient is minor.
Keywordssemi-immersed cylinder hydrodynamic coefficient forced oscillation experiment overtopping
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- Chakrabarti, S.K., 1987. Hydrodynamics of Offshore Structures, WIT Press, UK.Google Scholar
- Doynov, K.I., 1998. A Dynamic Response Model for Free Floating Horizontal Cylinders Subjected to Waves, Ph. D. Thesis, University of Florida.Google Scholar
- Faltinsen, O.M., 1993. Sea Loads on Ships and Offshore Structures, Cambridge University Press, Cambridge.Google Scholar
- Keulegan, G.H. and Carpenter, L.H., 1956. Forces on Cylinders and Plates in an Oscillating Fluid, Vol.4821, US Department of Commerce, National Bureau of Standards.Google Scholar
- Kristiansen, D., 2010. Wave Induced Effects on Floaters of Aquaculture Plants, Ph. D. Thesis, Norwegian Institute of Technology.Google Scholar
- Mercier, J.A., 1973. Large Amplitude Oscillations of a Circular Cylinder in a Low-Speed Stream, Ph. D. Thesis, Stevens Institute of Technology.Google Scholar
- Sarpkaya, T., 1976. In-line and transverse forces on cylinders in oscillatory flow at high Reynolds numbers, Proceedings of Offshore Technology Conference, Houston Texas, Paper No. 2533.Google Scholar
- Sumer, B.M. and Fredsøe, J., 1997. Hydrodynamics around cylindrical structures, in: Kamphuis, J.W. (ed.), Advanced Series on Ocean Engineering: Volume 26, World Scientific, Singapore.Google Scholar