Development of a numerical hydrodynamic tank for ship motion simulation

In this paper, an integrated computational procedure for simulation of two-phase flow as well as floating and submerged body motions is presented based on a Volume of Fluid (VoF) - fractional step coupling. Two fluids are modeled as a single continuum with a fluid property jump at the interface by solving a scalar transport equation for volume fraction. In conjunction, the conservation equations for mass and momentum are solved using fractional step method. Based on integration of stresses over a body, acting forces and moments are calculated. Using the strategy of non-orthogonal body-attached mesh and calculation of motions in each time step, result in time history of floating or submerged body motions. To verify the accuracy of the numerical procedure in simulation of two-phase flow, sloshing and dam breaking with obstacle problems are investigated. Besides, motions simulation strategy is evaluated by using cylinder water entry test case. To demonstrate the capability of simulation, barge resistance is calculated in two cases of fixed and free motion (2-DoF). All of the results are in good concordance with experimental data. The present method can be extended for full nonlinear motion of ships in waves