  We numerically investigate the effect of non-condensable gas inside a vapor
bubble on bubble dynamics, collapse pressure and pressure impact of spherical
and aspherical bubble collapses. Free gas inside a vapor bubble has a damping
effect that can weaken the pressure wave and enhance the bubble rebound. To
estimate this effect numerically, we derive and validate a multi-component
model for vapor bubbles containing gas. For the cavitating liquid and the
non-condensable gas, we employ a homogeneous mixture model with a coupled
equation of state for all components. The cavitation model for the cavitating
liquid is a barotropic thermodynamic equilibrium model. Compressibility of all
phases is considered in order to capture the shock wave of the bubble collapse.
After validating the model with an analytical energy partitioning model,
simulations of collapsing wall-attached bubbles with different stand-off
distances are performed. The effect of the non-condensable gas on rebound and
damping of the emitted shock wave is well captured.
