Vapor bubble nucleation in flowing liquids

A previously developed stochastic diffuse interface model coupled with the Navier-Stokes equations has been exploited to numerically investigate vapor nucleation in non-equilibrium systems (a flowing liquid). Both homogeneous and heterogeneous nucleation are addressed and the influence of macroscopic flows on nucleation observables is discussed. The extended mesoscale simulations allow us to infer the spatial distributions of the nucleated bubbles via Voronoi tesselation analysis and to represent the nucleation phenomenon as a stochastic Random Poisson Point process. Unexpectedly, the effect of the shear on nucleation rate is found to be nonlocal. An explanation of this puzzling behavior is proposed, based on the structure of the density field along the minimal free-energy path along the transition, which is evaluated using suitable rare events techniques.