Hydrodynamic Analysis Of Fishing Vessel’s Turning Motion Considering The Effect Of Floating State

When fishing boats are avoiding collisions or entering and leaving ports,the pilot needs to have a good understanding of ship maneuverability.Sailing attitude would experience many changes when ship entering shallow water,due to the hydrodynamic interaction between ship hull and seabed which can be expressed in a significant increase in resistance,sinkage and trim and can engender the safety of ships.It is very important to predict the hydrodynamic force of the rotating motion of the fishing boat in shallow water and analyze the surrounding flow field.With the development of fluid mechanics theory and computer technology,the research technology of ship fluid mechanics using CFD technology has become increasingly mature,and it is an economical and efficient research method.In this paper,the CFD method is used to numerically simulate the turning motion of the ship.First,the Osaka tanker with more reference data is selected as the research object to verify the accuracy of the numerical simulation method.The turbulence model selects SST k-ω,the technique of overset grid is used to release the three degrees of freedom,i.e.roll,pitch and heave.The numerical simulation results are in good agreement with the experimental data of F.berth,which verifies the feasibility of the method.Subsequently,the large tuna seine fishing vessel was used as the model to simulate the turning motion,change the turning speed and water depth,observe the hydrodynamic coefficient,the hull surface pressure and the surrounding flow field changes.The analysis of hydrodynamic force can provide some advices for ships sailing in shallow water.