Research On The Dynamic Response Of The Liquid Tanker With Sloshing

With the increasing exploitation of marine oil and gas resources,liquid cargo ships needs are growing in the current international market because of the advantages of high transportation efficiency and low costs.Liquid tanker is with the structure charactices of large width and the load characteristics of high depth.In a certain frequency range,ship motion will result in tank sloshing,and the sloshing influence seriously on hull structure strengthen and motion response,furtherly affects the operating efficiency and security of liquid cargo ship.It is of important application value to predict effectively the coupling motions of ship and liquid,and to assess structure strength thinking about the liquid sloshing.This thesis mainly consists of three parts.(1)Basic principle and numerical simulation method are studied.A unified approach where are the interior wetted surfaces of the tanks are includes as an extension of the conventional computational domain defined by the exterior wetted surface of the body is adopted considering the sloshing replease the additional mass term into the equation of motion in frequency domain based on linearized potential flow theory.The numerical calculation research on the coupled motion of FPSO and tank sloshing in different fillings and different directions is carried on,then compared with the FPSO model experment which is conducted by MARINE.The calculation accuracy and the computational efficiency are testified.(2)The coupling of ship motion with liquid sloshing in frequency domain is studied.The motions of 11000 DWT tanker are simulated,with or without liquid sloshing,with different filling rates,under different wave directions and with different longitudinal bulkhead.Through the results comparisons from different loadcases,the influence rules from liquid sloshing,filling rates,wave directions and structure stytle on ship motion are accomplished.(3)Structural strength of the liquid tanker is studied.The long-tern analysis of wave induced load of the 11000 DWT tanker is carried out,then the design wave method is used to study the structure response of the vessel with or without liquid sloshing.And then,the damage of typical fatigue nodes in ship cargo are predicted.The response of tank structure is analyzed by sloshing influence.