Shear thickening of dense suspensions: The role of friction

Shear thickening of particle suspensions is caused by a transition between lubricated and frictional contacts between the particles. Using three-dimensional (3D) numerical simulations, we study how the interparticle friction coefficient (mu(m)) influences the effective macroscopic friction coefficient (mu) and hence the microstructure and rheology of dense shear thickening suspensions. We propose expressions for mu in terms of distance to jamming for varying shear stresses and mu(m) values. We find mu to be rather insensitive to interparticle friction, which is perhaps surprising but agrees with recent theory and experiments. Unifying behaviors were observed between the average coordination numbers of particles across a wide range of viscous numbers and mu(m) values. Published under license by AIP Publishing.