A comparative study of wave kinematics and inline forces on vertical cylinders under Draupner-type freak waves

This study focuses on predictions of wave kinematics and inline forces acting on vertical cylinders concerning a series of Draupner-type freak waves. Multiple hydrodynamic models were introduced by using different stretching models for wave kinematics and different inertia coefficients of the Morison formula, and their applicability was assessed by comparisons with experimental measurements. It demonstrates that the modified Wheeler stretching method (Molin, 2002) could give satisfactory predictions of particle velocities and inline forces of Draupner-type freak waves. The drag force term is not negligible for slender structure, and frequency-independent inertia coefficients are preferred in Morison predictions. The high-frequency force components of small quantities are found to be responsible for the discrepancies between predictions and measurements.