Numerical Simulation On Motion Responses Of Moored Vessels Under Wind And Waves

With the development of port constructions,some overseas ports are affected by long period waves,which have characteristics of long period(generally more than 10)and large wave energy,and the vessels inside of port will also be damaged by these long peried waves.However,now the berthing stability are ensured by the limitations of wave height and wind velocity.Therefore,researching the external force loaded on the vessels,mooring system,and the berthing stabilibity of vessles under long period wave have great significance for improving the efficiency of vessel operation and port safety.In order to understanding the vessels berthing stabibility under long period waves,based on OpenFOAM,a three-dimensional numerical wave-wind flume was estabilited,which take into account the effect of wave and wind.Simulation investigation on motion response of moored vessel,mooring cable and fender force were carried out.The main contents and conclusions of this thesis are as follows:(1)Based on three-dimensional wave flume,wave-wind-maker boundary condition was implanted,and a more stable form of turbulence model was used.According to the physical model experiment,corresponding cases were set up to verificate the wave-wind-maker boundary condition,and analysising the influence of grid scale of wind field on simulation.The numerical simulation results are in good agreement with the experimental results.(2)Based on the MOODY(mooring cable dynamics),vessel-fender collision model was implanted.Rolling free decay of C11 ship and motion response of a moored LNG vessel under wind-wave condition were simulated to verificate the established model.The simulation results indicating that the established model can simulate the motion response of moored vessles.(3)Based on the three-dimensional numerical wave-wind flume,multipal cases were set up and the influence of wave period,wave height,distance between moored vessel and fender,wind velocity on vessel berthing stability was discussed according to the numerical model results,and the safe ranges of wave height and period of incident wave for moored vessels were geven.