Bubble Dynamics Characteristics Near Double-Layer Cylindrical Structures with a Hole Based on PIV Experiments

After the outer shell of the double-shell submarine is damaged by the near-field underwater explosion shock wave, the subsequent bubble pulsation and jet load will continue to cause serious damage to the inner shell of the submarine. Therefore, it is of great significance to study the characteristics of bubble pulsation and bubble load near the hole. Based on the double-shell submarine structure damaged by the shock wave, a double-layer cylindrical structure model with a prefabricated circular hole is made. Using an electric spark device as the bubble generator, the interaction experiments between bubbles and double-layer cylindrical structure with a hole under different explosion distance parameters (the ratio of explosion distance to the maximum diameter of bubbles) and different hole parameters (the ratio of hole diameter to the maximum diameter of bubbles) are carried out. A high-speed camera is used to capture the bubble pulsation and jet formation process near the double-layer cylindrical structure. The particle image velocimetry technology is used to test the velocity of the explosion flow field to obtain the jet velocity after the bubble collapse. At the same time, a pressure sensor is used to measure the pressure load on the inner cylindrical shell wall. The experimental results show that the detonation distance parameters determine the form of pressure load on the inner wall, whether effective jet is generated after the bubble collapse, and the jet velocity. When the detonation distance parameters are within a certain range, the hole parameters will affect the bubble pulsation and the direction of the water jet generated after the bubble collapse.