Hydrodynamic Response of Spar with Single and Double Heave Plates in Regular Waves

Abstract

The motion response of floating structures should be adequately low to permit the operation of rigid risers along with dry well heads. Though Spar platforms have low heave responses under lower sea state, could become unacceptable in near resonance region of wave periods. Hence the hydrodynamic response, heave in particular, must be examined to ensure that it is minimized. To reduce heave motions, external damping devices are introduced and one such effective damping device is heave plate. Addition of heave plate can provide additional viscous damping and additional added mass in the heave direction which influence the heave motion. The present study focuses on the influence of heave plate on the hydrodynamic responses of Classic Spar in regular waves. The experimental investigation has been carried out on a 1:100 scale model of Spar with single and double heave plates in regular waves. Numerical investigation has been carried out to derive the hydrodynamic responses using ANSYS AQWA. The experimental results were compared with those obtained from numerical simulation and found to be in good agreement. The influence of disk diameter ratio, wave steepness, pretension in the mooring line and relative spacing between the plates on the hydrodynamic responses of Spar are evaluated and presented.

Estimation of the Motion Performance of a Light Buoy Adopting Ecofriendly and Lightweight Materials in Waves

“…Through a series of experiments, some approximation equations were developed to calculate the added mass of the floating cylinder with a separate heave plate, and the motion response of a vertical circular cylinder with a heave plate to a series of regular waves was examined by Zhu and Lim [20]. Sudhakar and Nallayarasu [21,22] investigated the influence of single and double damping plates on the hydrodynamic response of a spar in regular and irregular waves by experimental studies. Koh et al [23] performed free decay tests by experiments to obtain the viscous damping coefficients of a circular cylinder with a heave damping plate changing the porosity of the damping plate.…”