Related Experiment Video
Updated: Jul 6, 2026
11:03
An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Flow, ordering, and jamming of sheared granular suspensions
Denis S Grebenkov1, Massimo Pica Ciamarra, Mario Nicodemi
1Dip.to di Scienze Fisiche, Universitá di Napoli Federico II and INFN, Naples, Italy. denis.grebenkov@polytechnique.edu
Physical Review Letters
|March 21, 2008
Summary
This study reveals distinct flow regimes in granular suspensions under shear stress. An ordered flow state emerges at higher stresses, characterized by a viscosity drop, while jamming leads to kinetic arrest.
Area of Science:
- Rheology
- Granular Materials
- Complex Fluids
Background:
- Granular suspensions exhibit complex flow behaviors.
- Understanding their rheological properties under shear is crucial for various applications.
Purpose of the Study:
- To investigate the rheological properties of granular suspensions under constant shear stress.
- To map the flow diagram in the volume fraction-stress plane.
Main Methods:
- Constant volume molecular dynamics simulations were employed.
- The study analyzed the system's response across different volume fractions and shear stresses.
Main Results:
- A flow diagram was derived, showing disordered flow at low volume fractions and ordered flow at higher stresses.
- Viscosity scaling followed Bagnold-like behavior at low stress, diverging near the jamming point.
- An order-disorder transition was observed, marked by a sharp viscosity drop.
- A jamming region exhibited slow dynamics and kinetic arrest, analogous to glassy systems.
Conclusions:
- Granular suspension flow is highly dependent on shear stress and volume fraction.
- Distinct ordered and disordered flow regimes exist, separated by a critical transition.
- The jamming transition in these systems shares similarities with glass transitions in thermal systems.
Related Concept Videos
01:17Colloids and Suspensions
Children at play often make suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water known as tempera paint. These suspensions are heterogeneous mixtures composed of relatively large particles visible to the naked eye or seen with a magnifying glass. They are cloudy, and the suspended particles settle out after mixing. The suspended particles in a suspension settle out after some time of mixing. The separation of particles from a suspension is...
01:17Steady, Laminar Flow Between Parallel Plates
Understanding steady, laminar flow between parallel plates is essential for analyzing and designing flow in narrow rectangular channels, commonly found in various water conveyance and drainage systems. The Navier-Stokes equations govern fluid motion and are generally challenging to solve due to their nonlinearity. However, simplifications are possible in certain cases, like the steady laminar flow between parallel plates. For this scenario, we assume steady, incompressible, laminar flow.
01:09Colloidal precipitates
The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...
01:17Viscosity
When water is poured into a glass, it falls freely and quickly, whereas if honey or maple syrup is poured over a pancake, it flows slowly and sticks to the surface of the container. This difference in the flow of different kinds of liquids arises due to the fluid friction between the liquid layers and the liquid and the surrounding material. This property of fluids is called fluid viscosity. In this example, water has a lower viscosity than honey and maple syrup.
The SI unit of viscosity is...
The SI unit of viscosity is...
01:27Types of Fluids
Fluids can be classified into Newtonian and non-Newtonian fluids based on their response to shear stress. Newtonian fluids have a linear relationship between shear stress and the shear strain rate, following Newton's law of viscosity. Their viscosity remains constant regardless of the shear rate, making their behavior predictable and easier to analyze. Common examples include water, air, oil, and gasoline.
In contrast, non-Newtonian fluids do not follow Newton's law of viscosity, and their...
In contrast, non-Newtonian fluids do not follow Newton's law of viscosity, and their...
03:22Colloids
Children at play often make suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water known as tempera paint. These suspensions are heterogeneous mixtures composed of relatively large particles that are visible to the naked eye or can be seen with a magnifying glass. They are cloudy, and the suspended particles settle out after mixing. On the other hand, a solution is a homogeneous mixture in which no settling occurs and in which the dissolved...