The Influence of Edge Sharpness on the Heave Damping Forces Experienced by a TLP Column

摘要

Previous numerical investigations conducted by authors have found that two different regimes of heave damping forces experienced by a TLP column during "springing vibration" generally exist depending on Keulegan Carpenter number and frequency parameter range. Significant effect of a small corner radius (2percent of cylinder radius) at the cylinder bottom edge on the form drag has been found for a fixed oscillatory frequency (0.41 Hz) over the Keulegan Carpenter number range investigated. The present paper has further investigated the effects of the corner radius of a TLP column on the springing damping forces. It is found that the corner radius in general reduces the form drag exertedon the oscillatory cylinder, and the reduction is larger as corner radius increases. Two diffeent heave damping regimes (linear and non-linear) also exist, and the transition from linear to nonlinear damping regime is delayed due to the corner radius at the cylinder bottom edge.