Numerical analysis of pulsatile blood flow in healthy, stenosed, and stented carotid arteries is performed with the aim of identifying hemodynamic factors in the initiation, growth, and the potential of leading to severe occlusions of a diseased artery. The Immersed Finite Element Method is adopted for this study to conveniently incorporate various geometrical shapes of arteries without remeshi...

The bicontinuous inverse cubic phase (V2 phase) formed in amphiphilic systems consists of bilayer networks with a long-range order. We have investigated effects of oscillatory shear on the orientation of the V2 phase with space group Ia3d formed in a nonionic surfactant (C12E2)/water system by using simultaneous measurements of rheology/small-angle X-ray scattering. It is shown that grain refin...

The viscometric functions for shear flow as predicted by the inextensible reptating rope model have been analysed numerically and analytically. The results obtained are compared with the predictions of the Curtiss-Bird theory. It is shown that if the correlation length of the rope is small as compared to its contour length significant deviations from the Curtiss-Bird theory are obtained. Result...

In this study, a fluid-structure interaction analysis based on the application of patient-specific mechanical parameters of the aneurismal walls was carried out to predict the rupture side during an abdominal aortic aneurysm (AAA). Realistic geometry of the aneurysm was reconstructed from CT data acquired from the patient, and patient-specific flow conditions were applied as boundary conditions...

Arterial wall shear stress is widely believed to influence the formation and growth of atherosclerotic plaque; however, there is currently no gold standard for its in vivo measurement. The use of phase contrast MRI has proved to be challenging due to partial-volume effects and inadequate signal-to-noise ratio at the high spatial resolutions that are required. This work evaluates the use of spir...

We revisit Taylor dispersion in oscillatory flows at zero Reynolds number, giving an alternative method of calculating the Taylor dispersivity that is easier to use with computer algebra packages to obtain exact expressions. We consider the effect of out-of-phase oscillatory shear and Poiseuille flow, and show that the resulting Taylor dispersivity is independent of the phase difference. We als...

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 severe case of stenosis in coronary arteries results in turbulence in the blood flow which may lead to the formation or progression of atherosclerosis. This study investigated the turbulent blood flow in a coronary artery with rigid walls, as well as 80% single and double stenoses on blood flow. A finite element-based software package, ADINA 8.8, was employed to model the blood flow. The hemo...

An essential cofactor for the endothelial NO synthase is tetrahydrobiopterin (H4B). In the present study, we show that in human endothelial cells, laminar shear stress dramatically increases H4B levels and enzymatic activity of GTP cyclohydrolase (GTPCH)-1, the first step of H4B biosynthesis. In contrast, protein levels of GTPCH-1 were not affected by shear. Shear did not change protein express...

A new paradigm of rheological characterization, oscillatory simple shear with infinite forcing amplitudes, is introduced by Khair (J. Fluid Mech., vol. 791, 2016, R5). This pushes the technique of large-amplitude oscillatory shear (LAOS) to have two extremely large amplitudes (both strain-rate and strain), which we might call XXLAOS. Model-specific analytical predictions are derived for a suspe...