Shear flow significantly affects the transport of swimming algae in suspension. For example, viscous and gravitational torques bias bottom-heavy cells to swim towards regions of downwelling fluid (gyrotaxis). It is necessary to understand how such biases affect algal dispersion in natural and industrial flows, especially in view of growing interest in algal photobioreactors. Motivated by this, ...

A transonic air stream flowing over a rectangular cavity or enclosure is unsteady. At certain flow conditions, large scale oscillations develop in the shear layer which, for an open cavity, spans across the whole enclosure. The convected shear layer instabilities interact with the cavity geometry, they generate resonance, and induce large amplitude wall pressure fluctuations, aerodynamic pressu...

Endothelial cells (ECs) play a significant role in modulating arterial functions [1,2]. ECs are the interface between vessel wall and blood flow, and perform tasks such as the regulation of permeability and the sensing of fluid forces acting on the vessels’ walls. ECs have shown contrasting effects between laminar shear flow with a definite direction the “disturbed” shear seen at arterial branc...

BACKGROUND The endothelium acts as the sensor of shear stress and as the mediator of flow-induced changes in vessel tone and structure. The purpose of this study was to delineate the signal transduction pathway of flow-induced release of endothelium-derived relaxing factor (EDRF). METHODS AND RESULTS We used a shear stress apparatus (a modified cone-plate viscometer) to expose cultured endoth...

This paper details a joint numerical and experimental effort to investigate a transition process in a laminar separation bubble, with the emphasis being put on the numerical contribution. A laminar separation bubble is formed if a laminar boundary layer separates in a region of adverse pressure gradient on a flat plate and undergoes transition, leading to a reattached turbulent boundary layer. ...

We examine the transient flow of a negatively buoyant, laminar plume in an emptying filling box filled with porous medium. As the system reaches steady state, the box is partitioned into two uniform layers of different densities. However, the approach towards steady state is characterized by a contaminated layer that is continuously stratified. Whereas the presence of a continuous stratificatio...

Fluid shear stress alters the morphology and function of the endothelium by activating several kinases. Furthermore, shear stress potently inhibits apoptosis of endothelial cells. Since activation of Akt kinase has been shown to prevent cell death, we investigated the effects of shear stress on Akt phosphorylation. To test the hypothesis that shear stress interacts with the Akt kinase pathway, ...