Research On Hull Slamming Load Forecasting Method Based On Local And Whole Ship Models

As an industry with great economic development potential in the shipbuilding industry,large luxury cruise ships can mobilize consumption and create huge social and economic benefits.Because the bottom profile of the stern of a luxury cruise ship is flat and has a large outward floating structure of the bow,slamming is very easy to occur during navigation.It will not only affect the comfort of tourists,but also cause damage to the hull structure and endanger the personal safety of the crew.At present,the slamming load prediction of ship hull mainly adopts the slamming test method of local model vertical falling into water.It is necessary to further study the slamming load of model inclined falling into water and real ship test considering the influence of wave field.Aiming at a 130000 ton large luxury cruise ship,this paper forecasts the slamming load at the bow and stern of the luxury cruise ship through different ways of falling body slamming load model test and whole ship wave slamming load test,combined with numerical simulation calculation.The following research work has been carried out:(1)The two-dimensional and three-dimensional numerical simulation methods of hull structure slamming based on arbitrary Lagrange Euler(ALE)algorithm are studied,and the basic principle,key technology and specific process of the simulation method are introduced in detail,which provides theoretical support for the later simulation work.(2)Aiming at the problem of bow and stern slamming of luxury cruise ships,two-dimensional and three-dimensional model falling slamming load tests were designed and carried out.By comparing the test data of two-dimensional bow rigid body model and three-dimensional bow rigid body model,the influence of three-dimensional flow effect on ship slamming load is analyzed;The influence of elastic effect on slamming load prediction is studied by two-dimensional stern elastic model test;Through the three-dimensional stern rigid body model of the removable pod device,the influence of the pod device on the stern slamming load is analyzed;The effect of ship entry angle on bow and stern slamming load is studied by three-dimensional bow and stern model slamming test with inclination angle.(3)The numerical prediction method of slamming load of luxury cruise ship is studied.The slamming load of two-dimensional and three-dimensional bow and stern models is simulated by LS-DYNA software.The feasibility of the numerical method is verified by comparing with the experimental data.By comparing and analyzing the differences between two-dimensional and three-dimensional simulation results and test results,a reasonable numerical simulation and prediction method of slamming load is given.(4)The difference of slamming pressure distribution in the bow and stern area between cruise model whole ship test and falling body slamming test is compared and analyzed.The comparison of dimensionless slamming pressure peak coefficient obtained by the two test methods is given.Based on the two model test results and numerical simulation results,a reasonable prediction method of slamming load design value of luxury cruise ship is given.