December 8, 2021 @ 11:00 am – 12:00 pm

Speaker: Eric S. G. Shaqfeh (Lester Levi Carter Professor of Engineering, Stanford University)

Title: Particles Suspension in Elastic Fluids: Toward a “Swimming Rheometer”

Abstract: Rigid or flexible particles suspended in viscoelastic fluids are ubiquitous in the food industry (e.g. pastes), industrial molding applications (all composites and 3-D printed parts), the energy industry (e.g. fracking fluids), and biological fluids (i.e. swimming of bacteria in mucous). The mathematical description of these suspensions is remarkably still in its infancy, but a the real breakthrough in this area has been the development of 3D computational simulations of such viscoelastic suspensions including particle motion and particle level resolution of the elastic flow fields. These simulations will allow the principles which govern the simplest flows of such suspensions, which are now generally not understood, to become elucidated in the next decade. I will describe two problems that have been recently analyzed using these computational methods – including the shear thickening of such suspensions and the design of a mechanical swimmer that is sensitive to elastic fluid rheology.