Wormlike micelles are an important class of surfactant micellar architectures that find use in applications ranging from consumer products to energy and nanomaterials. Many wormlike micellar systems exhibit a flow instability known as shear banding, characterized by an inhomogeneous flow field. Although many of the proposed mechanisms and theories for shear banding revolve around fluid microstr...

AIMS Endothelial cells (ECs) constantly exposed to shear flow increase nitric oxide production via the activation of endothelial nitric oxide synthase. Nitric oxide-mediated S-nitrosylation has recently been identified as an important post-translational modification that may alter signalling and/or protein function. S-nitrosylation of endothelial proteins after shear flow treatment has not been...

We identify the sequence of microstructural changes that characterize the evolution of an attractive particulate gel under flow and discuss their implications on macroscopic rheology. Dissipative particle dynamics is used to monitor shear-driven evolution of a fabric tensor constructed from the ensemble spatial configuration of individual attractive constituents within the gel. By decomposing t...

A 1-D and 2-D cylindrical flow stability is investigated in this paper. A typical velocity profile in a shear layer with infection point is studied first. The fluid motion is decomposed to two parts: the rotational part and shear part. Linear stability analysis shows the rotational part (like rigid body) is stable but the shear part is unstable. Of course, the shear layer with inflection point ...

Numerical predictions of blood flow patterns and hemodynamic stresses in Abdominal Aortic Aneurysms (AAAs) are performed in a two-aneurysm, axisymmetric, rigid wall model using the spectral element method. Physiologically realistic aortic blood flow is simulated under pulsatile conditions for the range of time-averaged Reynolds numbers 50< or =Re(m)< or =300, corresponding to a range of peak Re...

Behavior of a dilute polymer solution in a random three-dimensional flow with an average shear is studied experimentally. Polymer contribution to the shear stress is found to be more than 2 orders of magnitude higher than in a laminar shear flow. The results indicate that the polymer molecules are strongly stretched by the random motion of the fluid.

We study a colloidal model based on population balances in the context of complex fluid rheology. Two typical particle microstructure kinetics, orthokinetic, collisions due to shear, and perikinetic, collisions due to Brownian motion, are found to appear at continuum as different flow behaviors - those having monotonic and non-monotonic flow curves, respectively. Solving the colloidal model tog...

• Dynamics of Sheared Granular Fluid Meheboob Alam In first part of this talk, I will briefly review the dynamics of sheared granular fluid, focusing on instabilities, patterns and bifurcations in plane shear flow. It is shown that a universal criterion holds for the onset of the shear-banding instability (for perturbations having no variation along the stream-wise direction), that lead to shea...

It is long known that for high-velocity fluid flow in porous media, the relation between the pressure drop and the superficial velocity is not linear. Indeed, the classical Darcy law for shear stress dominated flow needs to be extended with a quadratic term, resulting in the empirical Darcy-Forchheimer model. Another approach is to simulate the foam numerically through the volume averaging tech...

We study the stationary and transient behaviors of a microemulsion phase subjected to a shear flow. The system is described by a diffusion-convective equation that generalizes the usual Cahn-Hilliard equation. Nonlinear terms are treated in a self-consistent approximation. Shear, first and second normal stresses are calculated as momenta of the structure factor. Shear thinning is observed in st...