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Porous Media

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I study the dynamics of two phase flow in porous media with application in enhanced oil recovery. Using confocal microscopy and 3D micromodel of porous media, I investigate the effects of polymer flow on oil recovery, a common method of enhanced oil recovery known as tertiary polymer flooding. Polymer solution decreases the permeability of the medium and results in diversion of flow paths and increased viscous forces in some area and mobilization of oil.
I am interested in the dynamics of two immiscible fluids at pore level in porous media.

Microfluidics

I investigate the dynamics of emulsion in 2D porous media. Emulsion droplets are generated using glass capillary microfluics devices. The emulsion is injected into a 2D array of posts, fabricated using soft lithography. We follow the dynamics of droplet along with the changes in the flow of the ambient fluid using tracer particles.
The emulsion flows intermittently within the medium, switching between free flow and no motion when trapped in small pores. However, when a number of droplets are trapped local pressure increases and deform the droplets to pass through small pores.

Turbulence

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We use high speed stereoscopic imaging to study the motion of anisotropic particles in fluid flows. The dynamics of rod-like particles is different from the carrier flow, since these particles align with the directions of history of velocity gradients as they are advected by fluid flow.
We have measured the rotational dynamics of small tracer rods in turbulence and showed that the rotation rate of rods is suppressed due to the alignment of rods with the flow. and rods preferentially sample the flow since their orientations become correlated with the velocity gradient tensor.
In another series of experimental measurements in two dimensional chaotic flows, we have quantified the alignment of rods with the Lagrangian coherent structure of the flow.