MEAN DRIFT FORCES ON A SLOWLY ADVANCING VERTICAL CYLINDER IN LONG WAVES

Based on the far field momentum formulation, a potential flow analysis is derived for the case of low forward speed in the long wavelength limit. The well known mean drift force at zero forward speed is recovered, together with an expression for the wave drift force damping. Results are obtained showing the significance of this damping effect in comparison with a viscous damping term. The analysis also sheds light on a simplified theoretical procedure that has been proposed for predicting low frequency damping of arbitrary three dimensional bodies.