The frequency dependence of the phase field model(PFM) is studied. A simple PFM is proposed, and is tested in a laminar boundary layer. The Blasius’s laminar boundary layer solution on a flat plate is used for the flow pattern, and several frequencies are imposed on the PFM, and the decay times of the interfaces are obtained. The computations were conducted for three cases: 1) no-flow, and 2) a...

OBJECTIVE Atherosclerosis develops initially at branch points and in areas of high vessel curvature. Moreover, experiments in hypercholesterolemic mice have shown that the introduction of disturbed flow in straight, atherosclerosis-resistant arterial segments turns them highly atherosclerosis susceptible. Several biomechanical mechanisms have been proposed, but none has been demonstrated. In th...

The transition to turbulence in pipe flow does not follow the scenario familiar from RayleighBenard or Taylor-Couette flow since the laminar profile is stable against infinitesimal perturbations for all Reynolds numbers. Moreover, even when the flow speed is high enough and the perturbation sufficiently strong such that turbulent flow is established, it can return to the laminar state without a...

An experimental study was conducted to characterize the transient behavior of laminar flow separation on a NASA low-speed GA (W)-1 airfoil at the chord Reynolds number of 70,000. In addition to measuring the surface pressure distribution around the airfoil, a high-resolution particle image velocimetry (PIV) system was used to make detailed flow field measurements to quantify the evolution of un...

The turbulent pulsatile blood flow through stenosed arteries considering the elastic property of the wall is investigated numerically. During the numerical model validation both standard k-ε model and RNG K-ε model are used. Compared with the RNG K-ε model, the standard K-ε model shows better agreement with previous experimental results and is better able to show the reverse flow region. Also, ...

This study investigated the phenotypic characteristics of monoculture P. fluorescens biofilms grown under turbulent and laminar flow, using flow cells reactors with stainless steel substrata. The cellular physiology and the overall biofilm activity, structure and composition were characterized, and compared, within hydrodynamically distinct conditions. The results indicate that turbulent flow-g...

doppler ultrasound can provide important information about vascular problems through the analysis of blood flow wave-form. the purpose of this study was obtaining the normal images of color doppler and estimation of blood flow velocity parameters of femoral artery in rabbits. left and right femoral arteries of 8 healthy adult new zealand rabbits were evaluated. color and spectral doppler images...

In the 21 st Century, reducing the environmental impact of aviation will become an increasingly important priority for the aircraft designer. Among the various environmental impacts, emission of CO2 can be expected to emerge as the most important in the long term and reducing fuel burn to become the overriding environmental priority. Increasing fuel costs and the world’s limited oil reserves wi...

A simple pressure-based feedback control strategy for wall-transpiration control of incompressible unsteady two-dimensional channel flow was recently investigated by Aamo, Krstic & Bewley (2003). Nonlinear two-dimensional channel flow simulations which implemented this control strategy resulted in flow transients with instantaneous drag far lower than that of the corresponding laminar flow. The...

when flow passes over the tube bundles, energy of flow transfers to the tubes. the fluid induced vibrations (fiv) imposed on the tubes is one of the important problems in analyzing the tube bundles and causes several problems. in this work, first, laminar flow around circular cylinder asymmetrically in a channel is simulated. the reynolds number is 20 and 100. the lift forces to tube are not ze...