Motion Response of a Circular Cylinder With a Heave Plate In Waves

A heave plate attached at the bottom of the cylinder has a distinct advantage in reducing the motion responses of a floating circular cylinder by increasing added mass and damping coefficient. First of all, matched eigenfunction expansion method for a circular cylinder with heave plate are used to obtain the hydrodynamic forces. Secondly, the motion responses for a full-scale cylinder model are calculated using the BEM-based ANSYS AQWA commercial code. The characteristics of hydrodynamic forces (added mass, damping coefficient) and motion response are investigated for various heave plate conditions, such as size, submergence depth, and heaving frequency. It is found that the added mass plays an important role in determining the location of the resonant frequency, and the radiation damping is more important in reduction of motion amplitude at resonance.