Virtual Seminar"Patches of patches: Spatial fluctuations of elastic turbulence in porous media"Sujit Datta

Micro/Bio/Nanofluidics (Shen) Unit would like to invite you to the virtual seminar by Prof. Sujit Datta on October 19 (Monday).
 
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Date: Monday, October 19, 2020
Time: 9:00-10:00am
**Zoom session
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Join Zoom Meeting

https://oist.zoom.us/j/94651433100?pwd=REE0OG9ZTHN5M01QcFE1VVN2YlJLdz09

Meeting ID: 946 5143 3100
Passcode: 885614

Speaker:

Prof. Sujit Datta
Chemical and Biological Engineering
Princeton University

Title:

Patches of patches: Spatial fluctuations of elastic turbulence in porous media

Abstract:

Polymer solutions are often injected in porous media for applications such as oil recovery and groundwater remediation. As the fluid navigates the tortuous pore space, elastic stresses build up, causing the flow to become unstable at sufficiently large flow rates—a phenomenon often known as “elastic turbulence”. However, what physical factors determine the onset of this instability, and what its spatial and temporal characteristics are, remain unknown. Here, we use direct visualization in model porous media to address this gap in knowledge. First, we show that the spacing between pores strongly influences the flow: when the pore spacing is sufficiently small, the unstable flow in the different pores exhibits a surprising bistability due to the interplay between elongation and relaxation of polymers as they are advected through the pore space. Second, using full three-dimensional porous media, we show that the onset of unstable flow in each pore is akin to a second-order phase transition, arising due to the persistence of discrete patches of instability. Thus, unstable flow is patchy across the different pores of the medium. Guided by these findings, we directly link the energy dissipated by pore-scale fluctuations to the flow resistance through the entire medium, enabling prediction of the macroscopic transport behavior. Together, these results reveal the rich array of behaviors that can arise during the unstable flow of polymer solutions through porous media, and provide a general framework by which flow fluctuations can be predicted and controlled.

Biography:

Sujit Datta is an Assistant Professor of Chemical and Biological Engineering at Princeton University. He earned a BA in Mathematics and Physics and an MS in Physics in 2008 from the University of Pennsylvania. He earned his PhD in Physics in 2013 from Harvard, where he studied fluid dynamics and instabilities in porous media and colloidal microcapsules with David Weitz. His postdoctoral training was in Chemical Engineering at Caltech, where he studied the biophysics and materials science of the gut with Rustem Ismagilov. He joined Princeton in 2017, where his lab studies soft and living materials in complex settings, motivated by challenges like clean oil/gas recovery, effective water remediation, and targeted drug delivery. Prof. Datta is the recipient of the NSF CAREER Award, the ACS Unilever Award, the APS Andreas Acrivos Award in Fluid Dynamics, the APS LeRoy Apker Award, the ACS Petroleum Research Fund New Investigator Award, and multiple Commendations for Outstanding Teaching.

Host:

Prof. Amy Shen