Comparative study on fluid dynamic behavior and slamming loads of two bow-flare sections entering into water

The accurate prediction of fluid-structure interactions during water entry is one of fundamental importance for the design of marine structures. However, our understanding of the impact physics largely relies on simplified wedges due to the difficulty in modeling complicated fluid flow such as flow separation and air cavity. In this paper, we proposed a comparative experimental study of generic bow-flare section to clarify the effect of bulbous bow on the fluid dynamic behavior, where two kinds of ship-like sections were chosen: one with a bulb at the bottom and the other without. Through a complete arrangement of sensors (including displacement sensors, accelerometers, and pressure sensors), a series of drop-test experiments was performed to elucidate the impact dynamics of the bow-flare section and the associated flow physics. In the comparative experiments, we systematically analyze the effect of the bulbous bow on the falling kinematics, free surface evaluation and slamming loads, indicating that the bulbous bow has a critical role on them. These findings offer evidence for a complex interplay between geometric parameters on the fluid dynamic behavior, which could improve our understanding of the impact mechanism of bow-flare section with bulbous bow.