Study Of Nonlinear Load Responses Of Ultra Large Container Ship

With the rapid development of the international shipping industry and the urgent requirements of the energy conservation and emissions reduction,the ultra large container ship has attracted increasing attention for the advantages of large cargo capacity and low transportation costs and carbon emission.The broad bow flares of the ultra large container ships will cause strongly nonlinear hydrodynamic in large amplitude waves,thus resulting the slamming pressure of the bow structure,which make it necessary to assess the nonlinear loads of the ultra large container ship.Aiming at the severe slamming pressure caused by the large-amplitude motion,this paper present a numerical analysis of slamming using a fully hydroelastic model,coupled with the 2-D boundary method,which can result nonlinear motion and wave loads of ships.Main contents are as follows:Firstly,this paper analyze the applicability of the different models on water impact problem,containing the Von Karman theory and the Wagner theory.Then the Wagner's theory is chosen as the initialization for the BEM method to calculate the slamming pressure.Secondly,based on the 2D Boundary Element Method,the numerical method is developed to simulate the water flow around a free-surface piecing body in order to calculate the added mass and slamming pressure.The pressure distributions on the body surface and the free surface profiles by the numerical calculations are compared with the similarity solutions for different deadrise angles to confirm the feasibility and validity of numerical method.Subsequently,the 3D nonlinear hydroelastic potential theory is analyzed and coupled with the 2D boundary method to calculate the motion and nonlinear wave loads of the ship,which are strongly coupled in time domain.Lastly,dividing the bow into several sections,the nonlinear motion and wave loads of the 10000TEU container ship in regular and irregular waves is calculated based on the coupled method and compared with linear results,gaining some conclusions.