Numerical Study On Hydrodynamic Characteristics Of Two Parallel Sailing Ships

Ships will continuously consume their stored materials when sailing and operating at sea.In order to improve the survival ability of long-distance ships and ensure the continuous combat effectiveness of combat ships,it is necessary to carry out sea replenishment.Among them,horizontal replenishment is dominant in the replenishment mode due to its advantages of many varieties and high efficiency.However,the hydrodynamic interference between the two ships may aggravate the ship's motion response,lead to supply difficulties or failures,and even lead to hull collision.Therefore,it is of practical and engineering significance to carry out numerical research on hydrodynamic characteristics of parallel sailing of the two ships.In this paper,combined with RANS method,the hydrodynamic characteristics of two ships sailing in parallel in viscous fluid are numerically simulated based on overlapping grid technology.First of all,for the parallel replenishment process of the two ships,the amplitude analysis of the response under regular waves in the whole wave direction is carried out,and then the motion response under irregular waves is predicted,and at the same time the lateral force and yaw moment of the two ships under different waves in the waves are calculated.The results show that the amplitude of motion response when waves are incident from both sides of two ships is larger than when waves are incident from head to tail of two ships.Under different waves,after ?/Lf=1/?/Ls=0.8,the motion response amplitude of the two ships both increased greatly.When?/Lf=0.5/?/Ls=0.3 and ?/Lf=1.25/?/Ls=1,the lateral force and yaw moment of the two ships both increased greatly.The receiving ship's 0-180 wave direction oscillation has a sense amplitude greater than 180-360 wave direction oscillation,and the supply ship's 0-180 wave direction oscillation has a sense amplitude less than 180-360 wave direction oscillation.Then,the influencing factors of hydrodynamic characteristics of the two ships sailing in parallel are analyzed from the perspective of replenishment conditions and dimensions of the replenishment ships.The results show that the longitudinal position has a great influence on the lateral force and yaw moment of the two ships.During the approaching and departing process of the two ships,the bow and stern of the two ships are close to each other and collision is easy to occur.Increasing the lateral spacing and reducing the speed can reduce the yawing,lateral force and yawing moment of the two ships.The captain and width of the supply ship should beappropriately increased to reduce the displacement gap between the supply ship and the receiving ship.Finally,based on the orthogonal test method,the optimization method of two ships' lateral replenishment scheme is studied,and the calculation results are analyzed by the method of intuitionistic analysis and variance analysis.The optimal two ships' lateral replenishment scheme is obtained,and the significant degree of the influence of the two ships' lateral position,longitudinal position and speed on the sway of the receiving ship is analyzed.