Numerical Study On Hydrodynamic Interaction Between Ships

Humans use offshore platforms to exploit marine resources and use ships to transport resources.However,offshore platforms have limited life and need to be dismantled and recycled.It always needs multiple ships to work together in the disassembly and recovery of offshore platforms,ship collisions are highly prone to occur during the process.Barges are the common ships in common operations.A barge will encounter,chase or travel through another barge when it is in the way to its designated location.When two barges meeting or overtaking,the dangerous accidents always occur because of the hydrodynamic interaction between two ships which affects their forces and movements.Therefore,it is very important to explore the hydrodynamic interaction.In this thesis,the commercial CFD software STAR-CCM+ is used to study the hydrodynamic interaction between barges numerically.Based on mathematical model of ship motion.The overset mesh is used to calculate the hydrodynamic interaction of the barges in the meeting or overtaking condition.By solving the unsteady RANS equations using the Realizable k-? turbulence model,the forces and the moments of barges can be calculated.The effectiveness of this numerical method is verified by predicting the static water resistance of a LNG ship.Then the effects of roll,sway and sway on the hydrodynamic interaction of ship-to-ship are analyzed,and the effects of ship speed ratio,lateral spacing and scale ratio on the hydrodynamic interaction between ships are calculated.The two-ship overtaking is simulated.The changes of the force and movement are analyzed.The interaction of ship speed ratio and lateral spacing on the hydrodynamic interaction between ships are explored.Finally,a ship passing through the mooring ship is calculated.The changes of the force and movement are analyzed.The numerical method proposed in the thesis could predict the hydrodynamic interaction of barges.It can provide some reference value for the model test research about barge's meeting and overtaking.It can also be used to the safe work of barges in the disassembly and recovery of the offshore platforms.