Tangential Forces Govern the Viscous-Inertial Transition in Dense Frictional Suspensions.
Sudarshan Konidena1, Franco Tapia1, Alireza Khodabakhshi1
1Technische Universität Dresden, Institute of Urban and Industrial Water Management, 01062 Dresden, Germany.
Physical Review Letters
|July 7, 2026
Summary
Dense granular suspensions transition from viscous to inertial flow around a Stokes number of 8. Particle pressure changes faster than shear stress during this transition, influenced by contact forces and jamming proximity.
Area of Science:
- Physics
- Rheology
- Granular Mechanics
Background:
- Dense granular suspensions exhibit complex flow behaviors.
- Understanding the transition from viscous to inertial flow is crucial for predicting suspension dynamics.
Purpose of the Study:
- To investigate the viscous-inertial transition in dense frictional suspensions using particle-resolved simulations.
- To identify key parameters and forces governing this transition.
Main Methods:
- Particle-resolved simulations with pressure-imposed rheology.
- Systematic variation of fluid viscosity, shear rate, and granular pressure.
- Analysis of Stokes number, shear stress, and particle pressure dynamics.
Main Results:
- The viscous-inertial transition occurs at a Stokes number of approximately 8.
- Shear stress transitions more slowly than particle pressure.
- Transitional behavior is linked to the shift from rolling to sliding contacts, influenced by Stokes number and proximity to jamming.
Conclusions:
- The study elucidates the mechanisms behind the viscous-inertial transition in dense frictional suspensions.
- Contact forces (tangential and lubrication) and jamming distance are critical factors.
- Increasing interparticle friction impacts the transition dynamics.
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