Physics

Polymer science

Composite material

Materials science

Thickening

Mechanics

Dilatant

Classical mechanics

Shear (geology)

Physical Review Letters

A consensus has emerged that a constraint to rotational or sliding motion of particles in dense suspensions under flow is the genesis of the discontinuous shear thickening (DST) phenomenon. We show that tangential fluid lubrication interactions due to finite-sized asperities on particle surfaces effectively provide these constraints, changing the dynamics of particle motion. By explicitly resolving for the surface roughness of particles, we show that, while smooth particles exhibit continuous shear thickening, purely hydrodynamic interactions in rough particles result in DST. In contrast to the frictional contact model, the hydrodynamic model predicts negative first and second normal stress differences for dense suspensions in the shear thickened state.Received 2 May 2019Revised 24 July 2019DOI:https://doi.org/10.1103/PhysRevLett.123.138002© 2019 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasFrictionRheologyPhysical SystemsSuspensionsPropertiesShear thickeningTechniquesHydrodynamicsPolymers & Soft MatterFluid DynamicsCondensed Matter, Materials & Applied Physics

Alternative Frictional Model for Discontinuous Shear Thickening of Dense Suspensions: Hydrodynamics