Arterial stenosis, for example Atherosclerosis, is one of the most serious forms of arterial disease in the formation of which hemodynamic factors play a significant role. In the present study, a 3-D rigid carotid artery with axisymmetric stenosis with 75% reduction in cross-sectional area is considered. Laminar blood flow is assumed to have both Newtonian and non-Newtonian behavior (generalize...

Much effort has been undertaken for the estimation of propulsive force of swimmers in the front crawl. Estimation is typically based on steady flow theory: the so-called quasi-steady analysis. Flow fields around a swimmer, however, are extremely unsteady because the change direction of hand produces unsteady vortex motions. To evaluate the force correctly, it is necessary to know the unsteady p...

The instability of supersonic compression ramp flow is investigated. It is assumed that the Reynolds number is large and that the governing equations are the unsteady triple-deck equations. The mean flow is first calculated by solving the steady equations for various scaled ramp angles α, and the numerical results suggest that there is no singularity for increasing ramp angles. The stability of...

1. Introduction A great variety of flows with importance to practical engineering applications are inherently unsteady and virtually all of the Newtonian fluid flows in nature are turbulent. Therefore, it is natural and unavoidable to deal with unsteady turbulent flows when Computational Fluid Dynamics (CFD) techniques are applied to engineering design and industrial use. CFD for general fluid ...

Time-dependent flows of a Newtonian fluid through periodic arrays of spheres were simulated using the lattice-Boltzmann scheme. By applying a constant body force per unit mass to the fluid, a steady background fluid flow through the array of stationary spheres was first established. Subsequently, a small-amplitude perturbation to the body force, which varied periodically in time, was added and ...

Details of pressure distributions, on a two dimensional airfoil oscillating in pitch through stall, in a 0.8 0.8 m low-speed wind tunnel are presented. Pitching occurred about the airfoils quarter-chord axis. Pitch rate, Reynolds number, and oscillation amplitudes were varied to determine the effects on pressure and lift distributions. It was found that mean angle of attack and pitching amplitu...

The effects of unsteady bubble dynamics on cavitating flow through a converging-diverging nozzle are investigated numerically. A continuum model that couples the Rayleigh–Plesset equation with the continuity and momentum equations is used to formulate unsteady, quasi-one-dimensional partial differential equations. Flow regimes studied include those where steady-state solutions exist, and those ...

Compressible large-eddy simulations of turbulent flow over a wall-mounted hump with active flow control are performedand comparedwithprevious experiments. Theflow is characterizedby the unsteady separationbefore the steep trailing edge, which naturally reattaches downstream of the hump to form an unsteady turbulent separation bubble. The lowMachnumber large-eddy simulation demonstrated a goodpr...

Vector fields are a common concept for the representation of many different kinds of flow phenomena in science and engineering.Methods based on vector field topology have shown their convenience for visualizing and analyzing steady flow but a counterpart for unsteady flow is still missing. However, a lot of good and relevant work has been done aiming at such a solution. We give an overview of t...

Front propagation in two-dimensional steady and unsteady cellular flows is investigated in the limit of very fast reaction and sharp front, i.e., in the geometrical optics limit. For the steady flow, a simplified model allows for an analytical prediction of the front speed v f dependence on the stirring intensity U , which is in good agreement with numerical estimates. In particular, at large U...