Pattern Formation in Suspension Flows

Series/Event Type: 
Description: 
In this talk, we focus on two complementary flow configurations in which the presence of suspended particles drastically alters the dynamics of the fluid-fluid interface and leads to pattern formation. First, we observe a particle-induced fingering instability when a mixture of particles and viscous oil displaces air inside a 2D channel. Our experimental results show that the characteristics of fingering depend on the particle volume fraction and on the ratio of the particle diameter to gap size. A reduced model is also presented to rationalize the critical wavenumber of instability. In the second part of the talk, we discuss the result of injecting air into a packing of soft hydrogel beads that are saturated in water. We find that this new combination of buoyancy, capillarity, and elasticity under confinement leads to complex morphologies of air migration, as well as nontrivial dynamics in the amount of trapped air in the system. 
Speaker: 
Sungyon Lee, University of Minnesota
Location: 
Bowen Hall
Date/Time: 
Friday, December 6, 2019 - 12:30pm
Speaker Bio:
Dr. Sungyon Lee is a Benjamin Mayhugh Assistant Professor in Mechanical Engineering at the University of Minnesota. She completed her Ph.D. and M.S. in Mechanical Engineering at Massachusetts Institute of Technology, and B.S. in Mechanical Engineering at the University of California, Berkeley. Following a post-doc at Ecole Polytechnique and adjunct faculty position in Applied Math at the University of California, Los Angeles, she was an Assistant Professor in Mechanical Engineering at Texas A&M University from 2013-2017. Dr. Lee's fluid mechanics research group specializes in reducing complex physical phenomena into tractable problems that can be visualized with table-top experiments and solved with mathematical modeling. The physical systems of interest range from drops and bubbles, particle-laden flows, to two-phase flows through porous media.
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