Interaction of a single bubble and an elastic plate: Influence of the standoff distance

The objective of this study was to investigate the coupled dynamics of a collapsing bubble and the motion of a nearby elastic plate at different initial distances. This was achieved using a combination of experimental and computational models. In the experiments, high-speed photography was used to record the temporal and spatial evolution of the collapse of a single bubble near an elastic boundary under normalized standoff distances γ ranging from 1.0 to 3.3. Digital image correlation was used to synchronously record the motion of the elastic plate. For the numerical simulations, taking the fluid compressibility and boundary motion into account, the immersed-boundary method was introduced to simulate the interaction between the elastic plate and bubble collapse. The results show that, with different initial distances, the dynamic behaviors of the bubble, including oscillation time, impact mode, and energy conversion, are different, and this is caused by the elastic rebound of the plate. In addition, the direction and amplitude of the deformation of the elastic plate are also influenced by the impact effects during bubble oscillation and rebound. The combined form of these impact behaviors changes with initial distance, and there are three typical impact patterns: the shock-wave effect, jet-effect, and hybrid shock-wave and jet-effect modes. In particular, when γ < 1.5, the jet effect and hybrid impact forms, which are dominated by the high-speed jet, can result in asymmetric deformation and cause greater local damage to the elastic plate. Finally, we summarize the combined mechanisms that govern the impact of a collapsing bubble on an elastic plate.