New results are reported on the propagation of a vortex ring through immiscible fluid interfaces in the limit of high Weber number in microgravity and in I-G. The main objective of the tests is to detennine the effect of density and viscosity ratios on the dynamics of the interaction. It is shown that density ratio plays a controlling role in determining the outcome of the interaction. For smal...

In this paper, we investigate the oscillatory dynamics of the tank-treading motion of healthy human erythrocytes in shear flows with capillary number Ca = O(1) and small to moderate viscosity ratios 0.01 ≤ λ ≤ 1.5. These conditions correspond to a wide range of surrounding medium viscosities (4-600 m Pa s) and shear flow rates (2-560 s(-1)), and match those used in ektacytometry systems. For a ...

A biocompatible microemulsion system comprising of isopropyl myristate (IPM) as oil, tween 80 as a non-ionic surfactant and isobuthanol as co-surfactant was studied experimentally at 298.15 K. The pseudo-ternary phase diagram for the microemulsion system has been delineated at different surfactant to co-surfactant mass ratio of 1:1, 2.4:1 and 4:1. Some physico-chemical properties such as densit...

This study is motivated in part by the discrepancy that exists in the literature with regard to the dependence of the tank-treading frequency of red blood cells on the shear rate and suspending medium viscosity. Here we consider three-dimensional numerical simulations of deformable capsules of initially spherical and oblate spheroidal shapes and biconcave discoid representing the red blood cell...

Using the lattice Boltzmann multiphase model, numerical simulations have been performed to understand the dynamics of droplet formation in a microfluidic cross-junction. The influence of capillary number, flow rate ratio, viscosity ratio, and viscosity of the continuous phase on droplet formation has been systematically studied over a wide range of capillary numbers. Two different regimes, name...