Effect of Viscosity Ratio on Structure Evolution during Mixing/Demixing of Regular Binary Mixtures

Effect of Viscosity Ratio on Structure Evolution during Mixing/Demixing of Regular Binary Mixtures

Blog Article

We simulate the mixing (demixing) process of a quiescent binary mixture with a composition-dependent viscosity which is instantaneously brought from the two-phase (resp.one-phase) to the one-phase (resp.two- phase) region of its phase diagram.Our theoretical approach follows a standard diffuse-interface model of partially miscible regular binary mixtures wherein convection and diffusion are coupled via a nonequilibrium capillary force, expressing the tendency of the phase-separating system to minimize its free powell and mahoney bloody mary mix energy.

Based on 2D simulation results, we discuss the influence of viscosity ratio on basic statistics of the mixing (segregation) process triggered by a rapid heating (quench), assuming that the ratio of capillary to viscous forces (a.k.a.the fluidity coefficient) is large.

We show that, for a phase-separating system, at a fixed value of the fluidity coefficient (with the continuous phase viscosity taken as a reference), the separation depth and the characteristic length scale of single-phase microdomains increase monotonically for increasing values of viscosity ratio; however, for a mixing system the attainment of a single-phase equilibrium state by coalescence dragon ball lg disney and diffusion is retarded by an increase in viscosity ratio at a fixed fluidity for the dispersed phase.