Numerical Simulation Of Hydrodynamic Interaction Between Head-on Ship-ship Based On FLOW3D

Recently,with the rapid development of the international shipping industry,ship is moving towards large-scale and high-speed,and the port throughput is incrementing steadily.Such trend intensifies the density of ships in the waterway,which certainly increases the possibility of ship encounter and,eventually accidents between ships.The inter-ship hydrodynamic effect caused by the inter-ship effect and shore effect are considered as critical reasons behind them.Therefore,to guide ship handling and avoid collision,it is of great importance to conduct research on the hydrodynamic interaction of ships.In this paper,the numerical simulation method is introduced to study the hydrodynamic interaction of ships in head-on encounter in unrestricted and restricted waterway respectively.By using RNG k-? turbulence model and GMRES pressure solver based on FLOW3 D,a computational fluid dynamics tool based on RANS equation,this paper carried out the numerical simulation of hydrodynamic effects in infinite open water and restricted waterway.The influence of lateral distance between ships,ship speed,ship draft,water depth in channel and ship size on the hydrodynamic force of the head-on ships are studied.Models of peak of suction lateral force of head-on ships on unrestricted and restricted waters are constructed respectively,and the peak of suction longitudinal force model of the restricted waters is also built.The main research works are as follows:(1)The theory and numerical methods of the relevant viscous flow of FLOW3 D software are introduced,including mathematical equations of governing equations,boundary conditions,and grids.Three turbulence models,k-? model,k-? model and the RNG k-? model,are emphatically analyzed and the discrete and solved processes of the control equations are also analyzed.(2)Taking KVLCC2 as research object,numerical simulation of hydrodynamics of two ships in the deep-water channel of open water is carried out.Firstly,grid dependency verification is performed and the most appropriate grid type is selected.Secondly,by comparing k-? model,k-? model and RNG k-? model,RNG k-? model is selected as the turbulence model for simulation.Then,hydrodynamics force between two ships with different lateral distance between ships,ship speed,ship draft and ship size are calculated,and the influence of various factors on the hydrodynamic force are analyzed.Finally,considering the influence of lateral distance between ships,ship speed,ship draft,water depth in channel and ship type on the hydrodynamic force of the head-on ships,the peak of suction lateral force model of two ships in infinite open water is constructed.(3)Taking KVLCC2 as research object,numerical simulation of hydrodynamics of two ships in shallow-water channel of restricted water is carried out.Firstly,hydrodynamics force between two ships with different lateral distance between ships,ship speed,ship draft,water depth in channel and ship size are calculated,and the influences of various factors on the hydrodynamic force are analyzed.Secondly,considering the influence of lateral distance between ships,ship speed,ship draft,water depth in channel and ship type on the hydrodynamic force of the head-on ships,the peak of suction lateral force model and peak of suction longitudinal force model of two ships in restricted water are constructed.In this paper,the CFD method of RANS equation has been used to simulate the hydrodynamic of two encountering ships in open water and restricted waterway successfully.The influence of the target ship's draft on the hydrodynamic force of the local ship has been added in the peak of suction lateral force model and peak of suction longitudinal force model.This is an important supplement and optimization of the original ship force peak model,which can provide theoretical reference for further complex hydrodynamic research.