Detailed information about the flow field pattern is highly important in accurately predicting particle deposition sites in the human airway. Flow in the upper airway during heavy breathing can have a Reynolds number as high as 9300, and therefore presents turbulent features. Although turbulence is believed to have an important effect on the airflow and other transport processes in the bronchia...

The work on this theme will comprise a boundary layer analysis in channel flow. Here we will be looking at both the laminar and turbulent case of incompressible flow within the presence of shear stress and vorticity. This study for both cases is a very important concept to understand for boundary layers in channel flows. To accomplish this study, we used the Finite Element Method and Finite Vol...

The problem of disturbed flow in the laminar boundary layer is investigated when a heating element is located on the surface of the body. The flow is supposed to be laminar one. It is shown that the problem may be solved in terms of free interaction theory. The solution of linear flat problem is constructed. The results of asymptotic analysis are also presented.

OBJECTIVE The liver X receptors (LXRs) regulate a set of genes involved in lipid metabolism and reverse cholesterol transport. We investigated the mechanism by which shear stress regulates LXR in vascular endothelial cells (ECs). METHODS AND RESULTS Western blot showed that the protein level of LXRalpha and its target ABCA1 in the mouse thoracic aorta was higher than that in the aortic arch. ...

Different laminar flow control strategies are reviewed for the various instability mechanisms and their applications over the different flight regimes are discussed. Success stories are told and unresolved problems are discussed. Over the years, the crossflow instability has been the primary challenge for laminar flow control. Favorable pressure gradients used to stabilize streamwise instabilit...

Rapid, in situ, and label-free chemical analysis in microfluidic devices is highly desirable. FT-IR spectroscopic imaging has previously been shown to be a powerful tool to visualize the distribution of different chemicals in flows in a microfluidic device at near video rate imaging speed without tracers or dyes. This paper demonstrates the possibility of using this imaging technology to captur...

Cystic fibrosis (CF) is a chronic progressive pulmonary disorder caused by mutations in the CFTR (cystic fibrosis transmembrane conductance regulator) gene. A CF lung is generally characterized by obstructed airflow to an extent that leads to destruction of airway wall support structure. Airway resistance, resulting from both laminar and turbulent flow, is an important mechanical factor contrib...

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...