Bubble Nucleation, Growth, and Deformation in Shear Flows

Abstract

Phase transitions in fluids can be drastically altered by shear flow. Bubble deformation and thermal growth are investigated numerically by means of a three-dimensional volume-of-fluid method. Furthermore, the asymptotic case of nucleation in extremely superheated liquids is treated in the framework of a continuum theory based on the Cahn–Hilliard gradient model. It is found that there is always an interesting distinction of the value π/4 for the flow-induced orientation angle in the case of small shear rates. For a great variety of viscosity and density ratios, the bubble deformation and even the break-up radius as a function of the corresponding capillary number are obtained. The growth process including non-equilibrium contributions is calculated, too. The results indicate that shear is able to completely suppress classical nucleation under certain circumstances.