A Small Scale Field Experiment for Hydrodynamic Coefficients of Morison’s Forces in Random Waves

The paper deals with wave forces on vertical and horizontal cylinders through the Morison’s equation. In particular, the hydrodynamics coefficients on cylinders are investigated by means of two small scale field experiments in the Natural Ocean Engineering Laboratory (NOEL) of the Mediterranea University of Reggio Calabria, by analyzing two stationary random processes of time: the measured wave force F_a(t), and the wave force calculated with the Morison equation F_c(t). The kinematics in the Morison’s equation is obtained with the theory of wind-generated waves from the directional wave spectrum obtained from measurements of surface waves. Starting from the measurements a new approach is proposed for the evaluation of the hydrodynamic coefficients of Morison’s forces for random sea waves. Finally, the distributions of the peaks of the random wave forces, F_a(t), and F_c(t), is achieved.