Woodruff School of Mechanical Engineering



Flowing and clogging of soft particles and droplets


Prof. Eric Weeks


Emory University


Thursday, November 5, 2020 at 2:00:00 PM


https://primetime.bluejeans.com/a2m/live-event/hybwaajz Building


Ellen Mazumdar


We study the flow and clogging of generally soft particles: micron-sized oil droplets, centimeter-sized hydrogel particles, and simulated soft particles. We find that softness is a key factor controlling clogging: with stiffer particles or a weaker driving force, clogging is easier. Softer particles form less stable arches and thus reduce the probability of clogging. Our results suggest that prior studies using hard particles were in a limit where the role of softness is negligible, which causes clogging to occur with significantly larger openings. We also examine a complementary situation, where flow of oil droplets is driven by constant flux rather than constant force, and find intermittent clogging and avalanches.


Eric Weeks earned his undergraduate degree in engineering physics at the University of Illinois at Urbana-Champaign. ('Engineering' physics meant he had to take drafting and Fortran.) In 1997 he graduated with a Ph.D. in physics from the University of Texas at Austin, working in the Center for Nonlinear Dynamics with Prof. Harry Swinney. His dissertation was on experiments studying anomalous diffusion and atmospheric phenomena. He started a postdoctoral fellowship at the University of Pennsylvania with Prof. David Weitz and Prof. Arjun Yodh, and finished his postdoctoral work at Harvard University when the Weitz lab moved there. In January 2001 he joined the faculty of Emory University, where he is currently a Dobbs Professor of Physics. Since July 2018 he has also been the Director of Emory's Center for Faculty Development and Excellence.