Rigid heave plates increase the damping and added mass to reduce the heave response in floaters, i.e., semi-submersibles, tension leg platforms, and spars. This study proposes a spar with a flexible heave plate (fins mounted on springs) as an active fin that can be tuned to achieve the required hydrodynamic response characteristics. The experimental investigation has been carried out to assess the added mass and damping characteristics with different spring stiffness. The results are compared with a spar with a rigid heave plate. Experiments were conducted on a 1:100 scaled model to measure the heave responses in the free decay mode. Heave damping is also calculated numerically using Computational Fluid Dynamics (CFD) simulation and validated with the obtained experimental results. The results indicate that the flexible heave plate (fins attached with springs) significantly increases the system's heave damping and added mass.


Keywords: Classic Spar; Flexible fins; Computational Fluid Dynamics (CFD); Heave added mass; Heave damping; Heave plate