# Rheology of dilute cohesive granular gases

## TL;DR

This paper investigates the rheological behavior of dilute cohesive granular gases, deriving flow curves from kinetic theory and analyzing stability, clustering, and viscosity characteristics through theoretical and numerical methods.

## Contribution

It provides a theoretical and numerical analysis of the rheology of dilute cohesive granular gases, including flow curve derivation and stability conditions.

## Key findings

- Stable shear flow exists only above a critical shear rate.
- Viscosity in stable flow matches that of hard-core granular particles.
- Below critical shear rate, clustering occurs with viscosity approximated by cluster mean diameter.

## Abstract

Rheology of a dilute cohesive granular gas is theoretically and numerically studied. The flow curve between the shear viscosity and the shear rate is derived from the inelastic Boltzmann equation for particles having square-well potentials in a simple shear flow. It is found that (i) the stable uniformly sheared state only exists above a critical shear rate and (ii) the viscosity in the uniformly sheared flow is almost identical to that for uniformly sheared flow of hard core granular particles. Below the critical shear rate, clusters grow with time, in which the viscosity can be approximated by that for the hard-core fluids if we replace the diameter of the particle by the mean diameter of clusters.