Jeffrey Fredberg: Flow under pressure

Jeffrey Fredberg: Flow under pressure

While most people are largely unaware of the flow of air through their lungs, an asthmatic suffering an attack battles for every breath. After years of study, scientists still aren't sure what lies at the root of this problem. Jeffrey Fredberg has pursued this question for much of his career, seeking to understand it at every level. It's a chase that's spanned his 15 years running his own nonpr...

Fredberg and Subra Suresh

Numerical Simulation of Micropolar Flow in a Channel under Osciatory Pressure Gradient

We numerically investigate the pulsatile flow and heat transfer of a micropolar fluid through a Darcy-Forchhmeir porous channel in the presence of wall transpiration. We use the central difference approximations for the spatial derivatives, whereas the time integration has been performed by employing the three steps explicit Runge-Kutta method to obtain the numerical solution. It i...

Stability Analysis of Cassie-baxter State under Pressure Driven Flow

The Cassie-Baxter state is a phenomenon in which a liquid rests on top of a textured surface with a gas layer trapped underneath the liquid layer. This gas layer introduces an effective shear free boundary that induces slip at the liquid-gas interface, allowing for friction reduction in liquid channel flows. Multiple studies have shown that different surface configurations result in different f...

Permeability of electrospun fiber mats under pressure driven flow

Hydraulic permeability of electrospun fiber mats under flow-induced compression has been modeled and verified experimentally. The permeation model accurately estimates the changes in solidity, and hence the permeability of the electrospun mats, over a range of pressure differentials. The model is based on Darcy’s law applied to a compressible, porous medium, using Happel’s equation for the perm...