The Contribution of Hydrodynamic Damping Induced by Mooring Chains on Low-Frequency Vessel Motions
To compute the low frequency mooring forces of for instance a turret moored storage/production tanker exposed to survival conditions the hydro-dynamic excitation and reaction forces have to be known. The low frequency excitation is assumed to caused by the velocity dependent wave drift forces. The hydrodynamic reaction forces consist of the added mass forces, the low frequency viscous forces and the wave drift damping on the tanker and the damping forces acting on the chain legs. Although in the past several investigations on chain damping have been carried out, data on low frequency chain damping, however, are scarce.