Discontinuous shear thickening of a moderately dense inertial suspension of hydrodynamically interacting frictionless soft particles

TL;DR

This study shows that discontinuous shear thickening can occur in moderately dense suspensions of soft, frictionless particles due to particle inertia and softness, expanding understanding of DST mechanisms.

Contribution

It demonstrates that DST arises in inertial, soft particle suspensions even without hydrodynamic interactions, supported by simulations aligning with kinetic theory.

Findings

DST occurs at lower densities with particle inertia and softness.

Simulation results qualitatively match kinetic theory predictions.

DST can happen without hydrodynamic interactions in soft particle systems.

Abstract

We demonstrate that discontinuous shear thickening (DST) can occur even in moderately dense, inertial suspensions of hydrodynamically interacting, frictionless soft particles. Using the Lubrication-Friction Discrete Element Method, our simulations reveal that DST can emerge at lower particle densities, provided that both the inertia of the suspended particles and their softness are sufficiently pronounced. Furthermore, we show that, under these conditions, the DST behavior obtained from the simulation qualitatively agrees with that predicted by kinetic theory, even without accounting for hydrodynamic interactions. These findings expand the understanding of DST in soft particle systems and highlight the importance of particle inertia and softness in controlling rheological behavior.