  This paper proposes a diffusive wetting model for the weakly-compressible
smoothed particle hydrodynamics (WCSPH) method to simulate individual water
entry/exit as well as the complete process from water entry to exit. The model
is composed of a physically consistent diffusive wetting equation to describe
the wetting evolution at the fluid-solid interface, a wetting-coupled
identification approach to determine the type of fluid particles by taking into
account the wetting degree of the contacted solid, and a numerical
regularization on the fluid particles at fully wetted fluid-solid interface.
The accuracy, efficiency, and versatility of the present model are validated
through qualitative and quantitative comparisons with experiments, including
the 3-D water entry of a sphere, the 2-D water entry/exit of a cylinder, and
the complete process from water entry to exit of a 2-D cylinder.
