Partially liquefied vitreous humor is a common physical and biochemical degenerative change in vitreous body which the liquid component gets separated from collagen fiber network and leads to form a region of liquefaction. The main objective of this research is to investigate how the oscillatory motions influence flow dynamics of partial vitreous liquefaction (PVL). So far computational fluid d...

We developed a new lattice Boltzmann method that allows the simulation of two-phase flow of viscoelastic liquid mixtures. We used this new method to simulate a bubble rising in a viscoelastic fluid and were able to reproduce the experimentally observed cusp at the trailing end of the bubble.  2000 Elsevier Science B.V. All rights reserved.

In this paper, we will attempt to extract some principles concerning the flow-induced anisotropy which develops in the settling of particles in Newtonian and viscoelastic fluids. Our point-of-view is that the local microstructure, which is determined by the hydrodynamic interactions between neighboring particles, determines the global anisotropic structure of a fluidized suspension. The particl...

To understand observations of low Reynolds number mixing and flow transitions in viscoelastic fluids, we study numerically the dynamics of the Oldroyd-B viscoelastic fluid model. The fluid is driven by a simple time-independent forcing that, in the absence of viscoelastic stresses, creates a cellular flow with extensional stagnation points. We find that at O(1) Weissenberg number, these flows l...

Newtonian fluid mechanics, in which the shear stress is proportional to the strain rate, is synonymous with the flow of simple liquids such as water. We report the measurement and theoretical verification of non-Newtonian, viscoelastic flow phenomena produced by the high-frequency (20 GHz) vibration of gold nanoparticles immersed in water-glycerol mixtures. The observed viscoelasticity is not d...

We present a passive droplet sorting technique based on intrinsic viscoelastic fluid properties dependent on inner and outer fluid phase viscosity ratio (k-value), droplet deformability, and viscoelastic properties. We demonstrate sorting rates of >200 Hz of both homogeneous and heterogeneous sized droplet populations between 40-100 μm‟s and enrichment rates as high as 99%. We demonstrate sorti...

Experimental observations are reported for the laminar flow of a viscoelastic liquid through a symmetrical plane sudden expansion preceded by a gradual contraction from a square duct. As is well known, for Newtonian fluid flow above a critical Reynolds number the flowfield downstream of an expansion becomes asymmetric. For the viscoelastic liquid investigated here the asymmetry is greatly reduc...

Since the physical behavior of many tissues is shown to be viscoelastic, we propose a novel registration technique for medical images via physical principles of viscoelasticity. It allows the template and the target images to differ by large local deformations like viscous fluid and small local deformations like elastic solid. With an extra elastic term introduced, the proposed model constrains...

Multiple particle-tracking techniques were used to quantify the thermally driven motion of ensembles of naked polystyrene (0.5 µm diameter) microbeads in order to determine the microrheological characteristics around the gut mucosa. The microbeads were introduced into living ex vivo preparations of the wall of the terminal ileum and proximal colon of the brushtail possum (Trichosurus vulpecula)...

A simple model for a swimmer consisting of three colinearly linked spheres attached by rods and oscillating out of phase to break reciprocal motion is analyzed. With a prescribed forcing of the rods acting on the three spheres, the swimming dynamics are determined analytically in both a Newtonian Stokes fluid and a zero Reynolds number, nonlinear, Oldroyd-B viscoelastic fluid with Deborah numbe...