instruction: measurement of brachial artery diameter variation by ultrasound methods has commonly been used to test the endothelial function. it is known that the artery diameter is increased by flow stimulation. therefore in the present study, the effect of external obstruction, as flow stimulation, on the radial strain of the brachial artery was assessed. also the biomechanical behavior of th...

We examine the convective stability of hydrodynamic discs with full stratification in the local approximation and in the presence of thermal diffusion (or relaxation). Various branches of the relevant axisymmetric dispersion relation derived by Urpin are discussed. We find that when the vertical Richardson number is larger than or equal to the radial one (i.e. |Riz| ≥ |Rix|) and wavenumbers are...

A pressure-based computational fluid dynamics (CFD) code is employed to calculate the flow field and rotordynamic forces in a whirling, grooved liquid annular seal. To validate the capabilities of the CFD code for this class of problems, comparisons of basic fluid dynamic parameters are made to three-dimensional laser Doppler anemometer (LDA) measurements for a spinning, centered grooved seal. ...

The coupling between a bulk vortical flow and a surfactant-influenced air/water interface has been examined in a canonical flow geometry through experiments and computations. The flow in an annular region bounded by stationary inner and outer cylinders is driven by the constant rotation of the floor and the free surface is initially covered by a uniformly distributed insoluble monolayer. When d...

in this paper it is attempted to investigate the behavior of an inviscid flow in the meridional plane of an axial flow compressor. for this purpose the 3-d unsteady euler equations in cylindrical coordinate are averaged in tangential direction. therefore, the equations are reduced to a 2-d system. by averaging the tangential component of momentum equation, a blade force will result. axial and r...

ABSTRACT Axisymmetric magnetohydrodynamic (MHD) models are useful in studies of magnetized winds and non-linear Alfvén waves solar stellar atmospheres. We demonstrate that a condition often used these for the determination nearly vertical magnetic field is applicable to radial instead. A general divergence-free curvilinear coordinates self-consistently derived obtain correct variation field. Th...

In this study, inelastic constitutive modelling is considered for the simulation of shear-thinning fluids through a circular channel. Numerical solutions are presented for power-law inelastic model, considering axisymmetric Poiseuille flow through a channel. The numerical simulation of such fluid is performed by using the Galerkin finite element approach based on artificial compression method (...

In an experimental context, the contamination of air–liquid interface by ambient pollutants can strongly affect dynamics and stability a given flow. some configurations, interfacial flow even be blocked surface tension effects. A cylindrical free-surface driven slow rotating disc is considered here as generic example such effects investigated both experimentally numerically. We suggest simple n...

Azimuthal magnetorotational instability is a mechanism that generates nonaxisymmetric field pattern. Nonlinear simulations in an infinite Taylor-Couette system with current-free external field show, that not only the linearly unstable mode m = 1 appears, but also an inverse cascade transporting energy into the axisymmetric field is possible. By varying the Reynolds number of the flow and the Ha...

I present an extension of the thin layer approximation to non-axisymmetric bow shocks. By choosing a suitable set of curvilinear coordinates that matches the geometry of a generally distorted bow shock surface, I derive the fluid equations for the flow. Analytical expansions are given for the matter flow near the bow shock stagnation point. Numerical solutions are also obtained, by using a revi...