We study the rheology of cornstarch suspensions, a non – Brownian particle system that exhibits discontinuous shear thickening. Using Magnetic Resonance Imaging (MRI), the local properties of the flow are obtained by the determination of local velocity profiles and concentrations in a Couette cell. For low rotational rates, we observe shear localization characteristic of yield stress fluids. Wh...

Success of a drilling, workover or completion fluid can be directly attributed to its viscosity at the shear rate of interest. In practice, fluids are subjected to a wide range of shear rates; therefore, a thorough understanding of fluid rheology and the impact of shear is necessary to optimize fluid design. Ideally, high viscosity is desirable only under low shear rate conditions, and should d...

Platelet activation in blood flow under high, overcritical shear rates is initiated by Von Willebrand factor. Despite the large amount of experimental data that have been obtained, the value of the critical shear rate, above which von Willebrand factor starts to activate platelets, is still controversial. Here, we recommend a theoretical approach to elucidate how the critical blood shear rate i...

The phase inversion from a morphology of hydroxypropylcellulose in water ~HPC50%! droplets in polydimethylsiloxane ~PDMS! matrix to a morphology of PDMS droplets in HPC50% matrix can be induced by a change of shear rate, due to a viscosity ratio inversion. Such a process passing through four different transient morphological stages was studied by optical microscopy in a transparent shear device...

INTRODUCTION/PURPOSE Cycling is associated with a reproducible systolic anterograde and diastolic retrograde flow pattern in the brachial artery (BA) of the inactive upper limb, which results in endothelial nitric oxide (NO) release. The purpose of this study was to examine the impact of different types and intensities of lower limb exercise on the BA flow pattern. METHODS We examined BA bloo...

A dense mixture of granules and liquid often shows a severe shear thickening and is called a dilatant fluid. We construct a fluid dynamics model for the dilatant fluid by introducing a phenomenological state variable for a local state of dispersed particles. With simple assumptions for an equation of the state variable, we demonstrate that the model can describe basic features of the dilatant f...

following recent works of several authors like huilgol, bhattacharya etd. and javadpour et al., this paper is to contribute further to the literature of axial flow in a rotational coaxial rheometer. we consider axial flow of herschel bulkley mode1 between two concentric cylinders with the inner one rotating, while the outer cylinder is held stationary. an attempt has been made to direct the ana...

Lattice Boltzmann simulations are used to explore the behavior of liquid crystals subject to Poiseuille flow. In the nematic regime at low shear rates we find two possible steady state configurations of the director field. The selected state depends on both the shear rate and the history of the sample. For both director configurations there is clear evidence of shear-thinning, a decrease in the...

The blood serum rheological properties can open the door to many investigators to find the convenient therapy for many cases of radiation exposure. The present study aimed to investigate the rheological properties of rat blood serum at wide range of shear rates after whole body irradiation with 75Gy gamma radiation dose in vitro. Thirty healthy male Wistar-Kyoto rats weighing 200 gm were used i...

We study thermomechanical deformations of a viscoplastic body deformed in simple shear. The e€ect of material elasticity is neglected but that of work hardening, strain-rate hardening, thermal softening, and strain-rate gradients is considered. The consideration of strain-rate gradients introduces a material characteristic length into the problem. A homogeneous solution of the governing equatio...