Related Experiment Video
Updated: Mar 30, 2026
11:03
An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
9.1K
Anisotropy of weakly vibrated granular flows
Geert H Wortel1, Martin van Hecke1
1Huygens-Kamerlingh Onnes Lab, Universiteit Leiden, Postbus 9504, 2300 RA Leiden, The Netherlands.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|November 14, 2015
Summary
We experimentally studied how granular media anisotropy changes with flow rate and vibration. Anisotropy collapses with driving stresses, revealing a direct link and its crucial role in granular flow rheology.
Area of Science:
- Experimental physics
- Rheology
- Materials science
Background:
- Granular materials exhibit complex flow behaviors.
- Anisotropy, or directional dependence, is a key property influencing these flows.
- Understanding the relationship between stress and anisotropy is crucial for predicting granular material behavior.
Purpose of the Study:
- To experimentally investigate the anisotropy of vibrated flowing granular media.
- To determine how anisotropy depends on flow rate and vibration strength.
- To establish a link between driving stresses and anisotropy in granular flows.
Main Methods:
- Experimental setup to create and observe flowing granular media.
- Controlled variation of flow rate and vibration parameters.
- Measurement of anisotropy and driving stresses.
Main Results:
- Anisotropy significantly varies with flow rate and vibration strength.
- Anisotropy collapses when plotted against driving stresses, indicating a direct relationship.
- Shear stresses were found to vanish at small anisotropies.
Conclusions:
- The fabric anisotropy of granular media is directly linked to driving stresses.
- Anisotropy plays a critical role in determining the rheology of granular flows.
- The findings provide insights into the fundamental mechanics of granular materials.
More Related Videos
09:00Visualization of Failure and the Associated Grain-Scale Mechanical Behavior of Granular Soils under Shear using Synchrotron X-Ray Micro-Tomography
Published on: September 29, 2019
13.9K
11:51Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions
Published on: February 22, 2018
9.2K
Related Concept Videos
01:17Steady, Laminar Flow Between Parallel Plates
1.0K
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.
1.0K
01:28Irrotational Flow
1.2K
Irrotational flow is characterized by fluid motion where particles do not rotate around their axes, resulting in zero vorticity. For a flow to be irrotational, the curl of the velocity field must be zero. This imposes specific conditions on velocity gradients. For instance, to maintain zero rotation about the z-axis, the gradient condition:
1.2K
01:29Gradually Varying Flow
533
Gradually varying flow (GVF) in open channels describes situations where water depth changes slowly along the channel due to factors like non-uniform bed slope, channel shape variations, or obstructions. This flow type occurs when the depth adjusts gradually to balance gravitational forces, shear forces, and energy requirements, resulting in a low rate of depth change.Characteristics of Gradually Varying FlowGVF is commonly observed in natural streams, rivers, and canals, where flow depth...
533
01:22Couette Flow
1.3K
Couette flow represents the flow of fluid between two parallel plates, with one plate fixed and the other moving with a constant velocity. This configuration allows for a simplified analysis using the Navier-Stokes equations, which govern fluid motion under conditions of viscosity and incompressibility. For Couette flow, the assumptions include a steady, laminar, incompressible flow with a zero-pressure gradient in the flow direction. This flow type is beneficial for understanding shear-driven...
1.3K
01:18Newtonian Fluid: Problem Solving
1.1K
Newtonian fluids exhibit a constant viscosity, meaning their shear stress and shear strain rate are directly proportional. This property ensures a predictable and stable response to applied forces, maintaining a linear relationship between force and flow. Examples include water, air, and light oils, consistently demonstrating this proportional behavior regardless of external conditions.
A velocity gradient forms within the fluid when a Newtonian fluid is placed between two parallel plates, with...
A velocity gradient forms within the fluid when a Newtonian fluid is placed between two parallel plates, with...
1.1K
01:17Viscosity
7.9K
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...
7.9K