Dynamics of a Laser-Induced Bubble above the Flat Top of a Solid Cylinder-Mushroom-Shaped Bubbles and the Fast Jet

The dynamics of a laser-induced bubble on top of a solid cylinder is studied both experimentally and numerically. When the bubble is generated close to the flat top along the axis of the cylinder and its maximum radius exceeds the one of the flat top surface, it collapses in the form of a mushroom with a footing on the cylinder, a long stem and a hat-like cap typical for a mushroom head. The head may collapse forming a thin, fast liquid jet into the stem, depending on bubble size and bubble distance to the top of the cylinder. Several experimental and numerical examples are given. The results represent a contribution to understand the behavior of bubbles collapsing close to structured surfaces and in particular, how thin, fast jets are generated.

Automated summary

This study investigates the dynamics of a laser-induced bubble on top of a solid cylinder through experimental and numerical methods. The research findings show that when the bubble is generated near the flat top of the cylinder and its maximum radius exceeds that of the flat top surface, it collapses into a mushroom shape with a footing on the cylinder, a long stem, and a hat-like cap. Depending on the size and distance of the bubble to the top of the cylinder, the cap may collapse, resulting in a thin, fast liquid jet into the stem.