Cavitation bubbles collapsing and rebounding in a pressure gradient $\mathbf{\nabla }p$ form a “microjet” enveloped by a “vapor jet.” This Letter presents unprecedented observations of the vapor jets formed in a uniform gravity-induced $\mathbf{\nabla }p$, modulated aboard parabolic flights. The data uncover that the normalized jet volume is independent of the liquid density and viscosity and proportional to $\zeta \equiv |\mathbf{\nabla }p|R_0/\Delta p$, where $R_0$ the maximal bubble radius and $\Delta p$ is the driving pressure. A derivation inspired by “Kelvin-Blake” considerations confirms this law and reveals its negligible dependence of surface tension. We further conjecture that the jet only pierces the bubble boundary if $\zeta \gtrsim 4\times {10}^{-4}$.

• Received 6 July 2011

DOI:https://doi.org/10.1103/PhysRevLett.107.204501