Experimental research of bubble pulsation and jet under a double plate with circular hole

The pulsation and jet of underwater explosion bubble heavily affected by the boundary conditions. To explore the pulsation behavior and jet load of underwater explosion bubble near a damaged double structure, some double plates with circular hole were designed. The electric spark-generated bubble was employed to act as the underwater explosion bubble, and the experiment research on bubble pulsation and jet below the double plate with circular hole was carried out. The bubble pulsation and jet process were recorded by a high-speed camera, and the bubble jet load was measured by a wall pressure sensor. The results show that with the growth of the standoff distance, the bubble jet changes from the type I “gas-liquid two-phase jet” to the type II “gas-liquid two-phase jet”, and finally into the water jet. The load of the type I “gas-liquid two-phase jet” are characterized with high peak pressure with short duration in the initial pressure stage, and low pressure with long duration in the standing pressure stage. Whereas the type II “gas-liquid two-phase jet” feature high peak pressure with short duration in the initial pressure stage without standing pressure stage.