Mechanical and Civil Engineering Seminar
Mechanical and Civil Engineering Seminar Series
Title: "Chaos in Confinement: Using Polymers to Mix Fluids and Speed Up Chemical Reactions in Porous Media"
Abstract: Many energy, environmental, industrial, and microfluidic processes rely on the viscous flow of polymer solutions through porous media. These fluids are typically shear-thinning; however, these solutions can unexpectedly flow thicken when forced through confined, tortuous spaces such as in porous media. The reason why has been a puzzle for over half a century. In this talk, I will describe how by directly visualizing the flow in a transparent 3D porous medium, we have found that this anomalous flow thickening reflects the onset of an elastic instability in which the fluid exhibits chaotic velocity fluctuations reminiscent of inertial turbulence, despite the vanishingly small Reynolds number. In addition to characterizing this fascinating flow state, we have found that this phenomenon can be harnessed for improving mixing and the efficiency of flow-mediated chemical reactions — with implications for a broad range of processes that are typically limited by poor mixing.
Bio: Sujit Datta is a Professor of Chemical Engineering, Bioengineering, and Biophysics at Caltech, where his group integrates experiment, theory, and computation to study transport processes of complex fluids, gels, and microbes in complex environments. He is also Editor-in-Chief of Reviews of Modern Physics. Prior to moving to Caltech in 2024, Sujit was Associate Professor and Director of Graduate Studies of Chemical & Biological Engineering at Princeton University. Sujit's scholarship has been recognized by awards from a range of different communities, including three awards from the APS (Early Career Award in Biological Physics, Andreas Acrivos Award in Fluid Dynamics, and Apker Award), the Allan P. Colburn and 35 Under 35 Awards of the AIChE, Pew Biomedical Scholar Award, Arthur Metzner Award of the Society of Rheology, Unilever Award of the ACS, Camille Dreyfus Teacher-Scholar Award, NSF CAREER Award, and Soft Matter Lectureship of the Royal Society of Chemistry. Sujit received his undergraduate degrees in Physics and Mathematics at the University of Pennsylvania, his PhD in Physics from Harvard, and postdoctoral training at Caltech.