Reduced-Scale Experiment Study on the Protective Mechanism of Foam Coating Against Underwater Explosion Bubble Jet

Underwater explosion poses a serious threat to underwater structures. Flexible cover or sandwich plate can reduce the underwater explosion impact response of underwater structures, so it has become a research hotspot. Previous studies have focused on the protective mechanism of the cover against shock waves, which is suitable for underwater explosion at a long distance. Besides the shock wave, the high-speed water jet towards the structure produced when the explosion bubbles collapse is more deadly in the near-distance underwater explosion. In view of this situation, based on the dimensional principle, this paper deduces the scaling similarity relationship. Through the scaling model underwater explosion test, it is found that the cavitation micro-bubble group on the surface of the covering coating interferes with the process of the explosion bubble forming high-speed water jet, and the protection mechanism of the underwater explosion bubble jet of the foam covering steel plate is put forward.