Basic research for a treatment of brain embolism: The condition of the liquid jet generation due to a bubble collapsing inside a cylinder

The experiment of the interaction of an underwater shock wave with an air bubble inside a Teflon tube filled with gelatin was excuted to investigate the treatment of brain embolism by means of the impact of the liquid jet generated by interaction of a shock wave with a bubble. The shock wave was produced by detonating a micro-explosive pellet, the pressure profiles of the shock wave loading on the bubble were measured on the centerline of the tube, and the subsequent jet penetration was visualized by means of a high-speed camera. It was found that the pressure profiles inside the tube were different from that near a solid surface, and played important role on the liquid jet formation. The penetration of the jets inside the tube depended on the stand-off distance, which needed to be above 5 fold of the initial bubble diameter. The collapse jet velocity inside the tube was observed to be slower than that near a solid surface. The duration of the liquid jet formation inside the tube appeared to be longer than that near a solid surface.