force_chains_in_pureshear.mp4

Rheology of particles suspensions

Left, numerical simulations carried out by Ryhoei Seto, Wenzhou Institute, University of Chinese Academy of Sciences (China), on rigid particles immersed in a Newtonian fluid in a planar extensional flow.

figura.pdf

We are interested to the mechanical behavior of particle suspensions, the flow of rigid particles in a viscous fluid. Interesting features are, for example, particle pressure, difference in normal stresses, shear thickening. We develop a theoretical model that employs force and torque equilibrium of a typical pair of particles in the flow to determine a representative trajectory of particle pairs that contribute to the stress (on the left, the extensional flow condition). We use Stokesian Dynamics simulations to guide and test the theory. A continuum theory has been proposed with a relation between stress and strain rate that involves the second and fourth moments of the particle distribution function.

Collaborations

James Thomas Jenkins, Cornell University (USA)

Ryhoei Seto, Wenzhou Institute, University of Chinese Academy of Sciences (China)


Particle trajectories and particle number density in case of extensional flow (JFM, with Jenkins and Seto, 2020)