Mechanical Excitation of Offshore Tower Model

A large scale model of a bottom-pivoted, surface-piercing, cylindrical oil-drilling platform was built to obtain experimental data on hydrodynamic coefficients applicable to the structure. The wave force on the structure was simulated by a mechanical device in still water. Thus, the number of variables to calculate the drag and added mass coefficients associated with the structure for use in conjunction with the Morison Equation was reduced. For instance, water particle velocity and acceleration were eliminated from the equation. Test runs were made at different simulated sea conditions. Consistent drag and added mass coefficients were obtained using various data reduction techniques.