Numerical simulations of pore isolation and competition in idealized micro-spall process

•A robust computational method involving Free Surface approximation and Volume of Fluid with explicit geometric reconstruction is employed to model bubble dynamics for a large bubble cluster.•The choice of boundary conditions corresponds to “ballistic” expansion in which rapid expansion causes bubble isolation, subsequent deceleration leads in turn to a ‘competition’ phenomenon•These two regimes depend solely on Weber number, which is captured by the simulation results. Pressure evolution and appearance of regimes agrees with analytical predictions.•Original results could substitute a basis for modelling on a larger scale.