Influences of ice-water mixture on the vertical water-entry of a cylinder at a low velocity

The ice floating on water surfaces during winter significantly influences the water entry process of a cylinder. Therefore, it is crucial to evaluate the influence mechanism of the ice-water mixture during the water entry process. In this study, we used computational fluid dynamics (CFD) to simulate the process of a cylinder vertically entering the water (without floating ice) and ice-water mixture at a low speed based on the finite volume method (FVM), the volume of fluid (VOF) method, the continuum surface force (CSF) model and the overlap grid technology. Results showed that the initial splash shape had changed owing to the floating ice, leading to the absence of the surface closure of the cavity, resulting in a pressure difference change inside and outside the cavity. This significantly influences the characteristics of flow fields, hydrodynamic and motion characteristics of the cylinder. While the motion characteristics of the cylinder were not significantly affected by the thickness of the floating ice, the difference can be seen clearly compared with the case without floating ice. The results of this study can provide a beneficial reference for designing new cross-medium projectiles under extremely low temperature environments during winter.