An inertial bubble collapsing near a solid boundary generates a fast impulsive micro jet directed towards the boundary. The jet impact on the solid boundary can cause pitting, and this effect has been taken advantage of in surgeries such as when micro-bubbles are driven ultrasonically to cavitate in tissue and produce jets that are believed to induce the surgical effect. In this experimental investigation we are interested in the jetting from single cavitation bubbles near boundaries. By introducing a through hole in the boundary beneath a single laser-induced bubble it is hypothesized that the forming jet upon bubble implosion will proceed to penetrate through the hole to the other side and that it may be utilized in useful application such as precise surgeries. We study the cases of a bubble in an infinite medium, near a blank solid boundary, and above a hole in a solid boundary. We find in the case of the hole the unexpected formation of a counter jet that is directed away from the hole and into the bubble. These findings are contrasted to similar counter jetting behaviors from bubbles near boundaries with viscous and elastic properties.
Ignition of liquid droplets fuels under conditions of radiation-conductive heating in air
