Experimental drop test investigation into slamming loads on a truncated 3D bow flare model

Abstract

The 3D impact problem of generic vessels was investigated experimentally through a series of free drop tests. In the experiment, a larger scale truncated bow flare model whose shape is from the ship-lines was used. Experimental uncertainty is verified through analyzing the repeatability and hydroelastic effects and it is less than 5%. A complete dataset including the falling kinematics and slamming loads was provided for the validation of mathematical model, which is suitable for benchmarking generic vessels impacting water in 3-d flow regimes. In order to discuss the 3D effects, on the one hand, we formulated a VOF method to simulate water entry problem and provided the 2D numerical results for different ship-like sections of the bow flare model. The result shows the pressure obtained by 2D numerical method is about 25% larger than the experimental ones. On the other hand, we compared the pressure peaks by analyzing the influence of impact velocity against the space position. It suggests that the 3D effect is prominent nearby the bow while it is not so important in the other locations, and the complex fluid forms including flow separation and air cavity depended on the impact velocity greatly influences the pressure.