COMPARISON OF DRAG AND INERTIA COEFFICIENTS FOR A CIRCULAR CYLINDER IN RANDOM WAVES DERIVED FROM DIFFERENT METHODS

Tri Cao Mai, Mayumi Wilms, Arndt Hildebrandt, Torsten Schlurmann

Abstract


This paper presents results from experimental works to investigate wave loading on a vertical circular cylinder in random wave conditions in a wave flume with different water depths . In-line force coefficients (drag and inertia coefficient) are estimated from the measured pressures on cylinder’s surface at different elevations along the length of the cylinder. The wave kinematics are estimated by using different wave theories. Methods of max-min and least-squares (simplified by fit on wave-by-wave basis) are applied to determine force coefficients.

Keywords


Wave load; Morison equation; Drag and inertia coefficient; random waves.

References


Davies, M. J. S., Graham, J. M. R., Bearman, P.W., "In-line forces on fixed cylinders in regular and random waves". In Conf. on environmental forces on offshore structures and their prediction, pages 113 – 136, 101 Philip Drive, Norwell, MA 02061, 1990.

Heideman, J. C., Olsen, O.A., Johansson, P. I., "Local wave force coefficients".Volume IV, 1979.

Henderson,A. R., Zaaijer,M. B., "Hydrodynamic Loading on OffshoreWind Turbine Support Structures". Engineering Integrity Society,Volume 25, pp24-31, 2008.

Isaacson, M., Baldwin, J., Niwinski, C., "Estimation of drag and inertia coefficients from random wave data". Journal of Offshore Mechanics andArctic Engineering, 113 (2), pp. 128-136, 1991

Morison, J. R., O'Brien, M. P., Johnson, J. W. and Schaaf, S. A., "The Force Exerted by Surface Wave on Piles", Petroleum Transactions,American Institute of Mining Engineers 189: 149-154, 1950.

Sarpkaya, T., Isaacson, M., "Mechanics of wave forces on offshore structure". Van Nostrand Reinhold Company, New York, 1981.

Sumer, B. M., Fredsøe, J., "Hydrodynamics around cylindrical structures" (Revised Edition). World Scientific Publishing Co. Pte. Ltd., Denmark, 2006.


Full Text: PDF

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.