Influence of Scale Effects on the Dynamics of Water Entry Across the Air-Water Interface

This study investigates the scale effects of structures with different scaling factors under identical water entry velocities based on a high-accuracy numerical simulation technique for flow fields. By comparing water entry velocity, cavity evolution characteristics, flow field parameters, and turbulence properties, the differences between scaled and full-scale models are analyzed. The results indicate that surface tension effects are enhanced in the scaled-down models, and different scaled models exhibit consistent dimensionless velocity at the same dimensionless time. The scaled-down models demonstrate higher local flow velocity, while the full-scale model shows a more uniform flow distribution. Additionally, the scaled-down models have lower turbulent viscosity, faster pressure wave attenuation, and a greater influence of viscous forces. Moreover, the water entry of the scaled-down models amplifies the scale effect on the Q criterion. These findings reveal the impact of scale effects on the water entry process and provide a reference for experimental design and numerical simulations.