Investigation of heave damping characteristics of buoy form spar with heave plate near the free surface using CFD validated by experiments

A comprehensive study on spar with curved neck profile with a heave plate near the surface is made to assess the effect of geometry and location of heave plate on heave damping. A CFD-based approach is adopted to extract the damping and added mass by tracing the heave decay, and the results are validated with those from experiments. Free heave decay tests are conducted on scaled spar models (1:100 scale) in calm water and the results compare reasonably well with that obtained from the numerical model. The experiments conducted for heave motion response indicate a reduction in heave response at resonance. In addition, the effects of heave plate diameter ratio (1–2) and heave plate position to draft ratio (0–0.9) on the heave damping of buoy form spar have been studied numerically to identify the most favorable configuration in terms of heave damping.