In some extreme oceanic environments, large-scale rising bubbles may form due to subaqueous geological activities. When a vessel encounters such bubble storms during navigation, the low-density gas–liquid mixture alters local hydrodynamic conditions, significantly impacting vessel buoyancy and stability while posing critical safety risks. To investigate the motion characteristics of floating bodies when encountering low-density bubble streams, this paper employs an experimental research approach to thoroughly analyze the impact effects of large-scale rising bubbles on underwater suspended cylindrical structure. The experiments are carried out in a sufficiently large water tank, which not only ensures adequate water depth but also effectively reduces the interference of tank wall on the bubble rising process. Meanwhile, a cylindrical structure capable of approximate free suspension in water is designed, eliminating the constraints imposed by connecting components on the cylindrical structure's motion. Key parameters including hydrostatic pressure, initial distance, and gas pressure are analyzed to elucidate their influence on the coupling characteristics between bubbles and the cylindrical structure. Experimental investigation indicates that these critical parameters significantly alter the flow velocity characteristics of bubble-induced jets when they impact the cylindrical structure. Under specific conditions, low-pressure bubbles could generate a stronger impact on the cylindrical body compared to high-pressure counterparts. These findings aim to enhance the understanding of interaction physics between rising bubble and floating body, and provide engineering references for navigation safety under low-density bubble flows.
Lyu et al. (2026) studied this question.