Longitudinal Motion Simulation For High-Speed Vessels In Steady Water

Since the change of the flow field and stress around the hull,the hull gesture will change correspondingly during voyage.For high-speed vessels,the change are more obviously,which affect the normal sailing of the vessel,also reduce the comfort and safety of the ship.The six degree of freedom movement of ship is a complex three-dimensional flow,meanwhile,the motion of ship is very complicated,which,plus the free surface,increases the difficulty of the problem.With the rapid development of computer technology and CFD(Computational Fluid Dynamics),more and more scholars have conducted research with numerical method.In this thesis,based on CFD technology the hull resistance,longitudinal motion and retrofit design of high-speed vessel are conducted by means of CFD software STAR-CCM+.Firstly,in this thesis,it calculated the resistance of a certain type high-speed vessel under fixed and free model using CFD technology,and then compared the results of numerical calculation and experimental results,verifies the resistance obtained by using the free model with higher precision.Secondly,for the six degree of freedom movement of ship,the simulation for longitudinal motion of high-speed vessels in steady water was carried out and analyzed the influence caused by hull lines.The change of hull resistance under different speed,trimming angle and sinkage caused by ship motion and flow field distribution around the ship are presented.Finally,the simulation for DTMB5415 model which takes the heave and pitch coupling movement into account was presented on the basis of the numerical simulation for the six degree of freedom movement of ship,and the ball stem retrofit design was conducted.This could provide a certain degree reference to the numerical simulation for the motion prediction of high-speed vessels.