Numerical Simulation Of Movement Characteristics Of Container Ships In Restricted Waters And Countermeasures For Safe Navigation

This dissertation selects the standard ship type KCS developed by the Korea Institute of Marine and Marine Engineering(now MOERI),and the series of ship models that have undergone detailed pool tests as the calculation objects.Using the overlapping grid technology,it is solved by using Star-CCM+ RANS The ship has been numerically calculated for the hull sinking and trim at different speeds;the resistance increase and flow field characteristics of the ship sailing in shallow water are numerically studied,and the resistance and flow field of the ship at different speeds in shallow water are analyzed The law of variation has been numerically calculated for the drift of the ship in the curved channel;the relationship between the flow-induced drift in the curved channel and the radius of curvature of the curve,the speed of the ship,the draft of the ship,and the yaw angle of the ship have been calculated.The specific work is as follows.(1)The CFD method was used to conduct a numerical simulation study on the sinking and trim of a large container ship in shallow water.The comparison between the numerical results and the experimental values of the ship model pool proved the accuracy and effectiveness of the numerical method used.By comparing with the empirical formula,under the conditions of water depth draught ratio h/d=1.2 and h/d=1.5,when the speed is less than 12 kn,the Hooft formula can be used to quickly calculate and predict the sinking amount of the ship,to determine the safe surplus water depth,when the speed is greater than At 12 kn,the empirical formula cannot safely predict the amount of hull sinking.Under the conditions of water depth draught ratio h/d =1.2 and h/d =1.5,when the speed is less than 12 kn,the Turner formula can be used to overestimate the amount of ship sinking to ensure a fully safe surplus water depth.(2)Using the Star-CCM + RANS solver and considering the effect of free liquid surface and rudder on the ship's flow field,a numerical study was conducted on the ship's resistance increase and flow field characteristics of the ship sailing in shallow water.The law of resistance and flow field change at different speeds is used todiscuss the internal causes of the shallow water effect.It is concluded that when Fh =0.735,the ship is affected by the shallow water effect.As the speed increases,the ship's resistance jumps sharply when it is in the transcritical and supercritical regions.The increase in ship resistance is mainly due to the increase in wave resistance.The speed reduction can effectively slow the effect of shallow water drag increase and improve navigation safety.(3)By simulating the water flow in the bend,the characteristics of the flow in each position of the bend are understood.It provides theoretical support for the countermeasures of safe navigation of container ships.And write MATLAB program to draw intrinsic correlation diagram of radius of curvature,ship speed,draught size,yaw angle and flow-induced drift.(4)For container ships sailing in restricted waters,the navigation characteristics are summarized,and safe navigation strategies are proposed.