Far East Journal of Ocean Research
Volume 1, Issues 2-3, Pages 81 - 97
(December 2007)
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HYDRODYNAMIC COEFFICIENTS AND EXCITING FORCES OF A BUOY WITH A CENTER TUBE
Dong Xiuhong (P. R. China) and Wu Bijun (P. R. China)
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Abstract: A buoy with a center tube is often designed as a wave powered navigation device. The hydrodynamic fluid/solid interaction becomes more complex due to the center tube as compared with a single-form buoy. Linear potential theory is used to investigate the hydrodynamic coefficients and exciting forces for the device due to diffraction and radiation in water of finite depth. These are derived from the total velocity potential. A set of theoretical added mass, damping and exciting force expressions has been proposed. The numerical results show that the effects of the tube on the damping and the vertical exciting force at the buoy are ignored if the size of the tube is relative smaller. It is very interesting that the added mass of the complex circular buoy for heaving motion are smaller than that of a simple vertical cylinder for the product of the wave number and the radius of the buoy bigger than a special value. |
Keywords and phrases: analytical approach, velocity potential, added mass and damping, exciting force. |
Communicated by Hyo Choi |
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