Numerical Study on the Added Resistance of a Large Tanker in Regular Waves

초록

The increasing oil price and tight regulations for CO2 emission have led to increased interest in the resistance of a ship in waves. This paper presents a numerical simulation for flow around an advancing large oil carrier to calculate the added resistance and motion in regular waves. The numerical simulations and calculations are carried out using a fixed Cartesian grid system. At every computational time step, the moving hull is redefined by the intersection points of the body surface and the center line of each grid face. Partial-slip and divergence free conditions are imposed as the body boundary conditions. The pressure and velocity of the body boundary cells are calculated using the simultaneous iterative method. The nonlinear waves near the ship are simulated using the modified marker-density(MMD) method. The MMD method uses the practical densities of water and air. In addition, the pressure and velocity of a free surface cell are calculated using governing equations, which are the Navier-Stokes equations and continuity equation. Therefore, the MMD method defines the free surface more sharply than the volume of fluid or level-set methods. The objective ship modeled in this research is the KRISO Very Large Crude oil Carrier 2 (KVLCC2). During the numerical simulations, the heave and pitch motions are set free, but the other motions are set fixed. The characteristics of the added resistance and motions are investigated at various wave lengths.