Numerical investigation on the cavity dynamics and multiphase flow field evolution for water entry of vertical cylindrical shell

Abstract Water entry of vertical cylindrical shell is a nonlinear and unsteady process that involves the coupling of multiphase flow. In this paper, a numerical simulation of the water entry of vertical cylindrical shell is carried out with an objective to examine the physical mechanism of flow characteristics due to the effect of inner diameter. The numerical results are validated and verified against the experimental data. From the flow characteristics, the phenomena of cavitation closure can be identified as the cavity evolution the deep closure, the semi-closed mode and the non-cavity closure. The effect of inner diameter of cylindrical shell shows to have a significant influence on the cavity closure mode and time, and its geometry profile. The parametric study showed that the acceleration of cylindrical shell decreases with increasing inner diameter in the process of water entry. The formation of pressure, velocity and multi-scale vortices indicate the complex distribution of these components changing with space and time.