Numerical Modeling On The Interaction Effects Between Two Encountering Ships

The shipping business is sparked as the fast growth of Chinese economy in recent years, the number of ship is increasing continually that leads to the ports and rivers are overcrowded; the ship safety problem has cropped up. There are many problems that affect the safe navigation of the ship, some human factors, such as the vessel operators’ manipulation mistakes, while others are non-human factors, such as the accident caused by ship-ship hydrodynamic interference. The so-called hydrodynamic interaction is when the ship is sailing close to other ships or marine structures will cause changes in the flow field, and thus producesa certain amount of force and torque between ships or between ships and other marine structures, this often results in the ships collision. With the increasing in the density of ships, high-speed trend, the narrower waterways, all above these factors exacerbate the role of the hydrodynamic interaction, the ship-ship hydrodynamic interaction has been a important factorthat impacts the safe ship navigation.It has great significance for the safe navigation of ships to forecast the hydrodynamic interference accurately and intuitively. The traditional method, ship model experiment, is time-consuming and costly. This paper adopted an easy way to fully simulate interference between the ships. By using the dynamic mesh in Fluent, the governing equations of viscous flow and the equations of motion of the ships are solved, the six degrees of freedom ship-ship motion induced by the hydrodynamic forces is numerically simulated. By analyzing the numerical results at different relative speeds, longitudinal distances and ship sizes, the influences on the hydrodynamic force and moment are illustrated. To verify the validity of the present numerical methods, the calculated results are compared with those in published literature. On this basis, the viscous hydrodynamic flow field around two overtaking vessels is simulated, while the mutual interactions between them are considered.This paper has volumes written about the interaction effects between two encounteringships in two dimensions, compared with the three-dimensional problem, the biggest benefitwould be less computing time. For the three-dimensional problem, only appears at the endof the paper as a kind of supplement and comparison. The results of this study can predict intuitively the interaction effects between two encountering ships travelling in restricted water, it also can provide the safe guidance for ship maneuvering safety.