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Liquid Dam: A Constant-Speed Regime in Gravity-Driven Shear-Thickening Suspensions
Alexis Bougouin1, Henri Lhuissier1, Yoël Forterre1
1IUSTI, CNRS, Aix Marseille Univ, Marseille, France.
Physical Review Letters
|May 1, 2026
Summary
Shear-thickening suspensions form a constant-speed liquid dam when flowing, independent of volume or slope. This jamming front controls their gravity-driven dynamics in nature and industry.
Area of Science:
- Rheology
- Fluid Dynamics
- Material Science
Background:
- Shear-thickening suspensions exhibit increased viscosity under stress.
- Their behavior in gravity-driven flows is not well understood.
- These materials are common in natural phenomena and industrial applications.
Purpose of the Study:
- To investigate the dynamics of shear-thickening suspensions in gravity-driven flows.
- To understand the mechanism behind their spreading behavior.
- To develop a predictive model for their flow dynamics.
Main Methods:
- Experimental observation of suspension spreading.
- Analysis of the front's geometry and velocity.
- Development and application of a gravito-rheological model.
Main Results:
- Shear-thickening suspensions form a sharp, vertical front (liquid dam).
- The front advances at a constant speed, irrespective of volume, height, or slope.
- A jammed, frictional front localizes energy dissipation, decoupling flow from geometry.
Conclusions:
- The constant-speed spreading is governed by a jammed frictional front.
- A gravito-rheological model successfully predicts the observed flow regime.
- Shear thickening critically influences gravity-driven flows across various scenarios.
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