Numerical investigation on the water entry of a 2D seaplane section with heel angles

The accurate prediction of impact loads during water entry is the key to structural strength assessment. However, our understanding on the load characteristics mainly relies on the simplified geometrical shapes such as wedges and ship-like sections. This paper studied the water entry of a 2D seaplane section with the bottom cabin, which focuses on the formation of air cavity, the influence of the cabin to the flow and impact pressure. A compressible air-water two-phase model was established and the free surface was modeled by the VOF (Volume Of Fluid) algorithm. Numerical method was validated by the published experimental data and other numerical results showing good agreements. Some hydrodynamic characteristics related to water impact were discussed including the free surface, pressure distribution and pressure time history. The complicated flow (air cavity and jet flow impact) and obvious multiple pressure peaks were observed, which of them are different to the general impact phenomenon of simplified geometrical shapes. The influence of water entry velocity on the impact loads was further discussed, showing the multiple pressure peaks were affected by the impact velocity. Results of the study are expected to improve the understanding of impact mechanism of special sections with obvious air cavity flows.