Numerical simulation on the water entry of bow-flare section considering bulbous bow

The hydrodynamic problem of bow-flare section entering into water was studied through the CFD(Computational Fluid Dynamics) method. A two-phase compressible flow model was established based on N-S equations and modeled by VOF (Volume of Fluid) algorithm. The geometric reconstruction approach was adopted to track the free surface and a dynamic mesh approach is used to treat the body motion. The bulbous bow is included to clarify its effect on the impact hydrodynamics, where two kinds of ship-like sections were chosen: one with a bulb at the bottom and the other without. Impact hydrodynamic characteristics including falling kinematics, free surface and slamming loads are discussed, showing that the pressure nearby the bulbous bow is getting higher than the case without bulb, which should be paid attention in the ship structure design. Special attention is paid to the influence of water entry velocity on secondary impact and results show that water entry velocity has a significant effect on the first pressure peak.