Simulation of Droplet Deformation at Supercritical Capillary Numbers Using a Lattice Boltzmann Method
Frederick R. Phelan Jr., Nicos Martys, Charles C. Han
Lattice Boltzmann simulations have been carried out for two-phase systems in homogeneous shear flow at supercritical Capillary numbers and a viscosity ratio of unity. The simulations predict a three-stage mechanism for drop breakup. In the first stage, the drops are drawn into high aspect ratio liquid threads, with bulbous, dumbbell shaped ends. Once drawn, instabilities develop in the form of undulations in the cross-sectional area along the axis of the drop. In the final stage, the severity of the undulations causes child drops to pinch off from the ends of the main body until it is itself below the critical size. The child drops that form are all below critical, but are not wholly uniform in size. The greatest in size are the two drops that formed from the initial dumbbell shaped ends of the elongated thread. Subsequent drops are all smaller than this, and the distribution appears to be log-normal at high drop numbers. We find that the total number of drops that form scales according to a power law relation, and that for large enough ratios of the capillary number to its critical value, the total strain required to breakup the initial drop from 1 to N entities, appears to become constant.
Phelan Jr., F.
, Martys, N.
and Han, C.
Simulation of Droplet Deformation at Supercritical Capillary Numbers Using a Lattice Boltzmann Method, International Journal of Multiphase Flow
(Accessed September 26, 2023)