Related Experiment Video
Updated: Apr 21, 2026
11:03
An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
7.6K
Instabilities in granular binary mixtures at moderate densities.
Peter P Mitrano1, Vicente Garzó2, Christine M Hrenya1
1Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, USA.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|October 30, 2014
Summary
This study reveals critical length scales for instabilities in granular mixtures using advanced hydrodynamic equations. Findings show excellent agreement with simulations, validating the model for complex granular flows.
Area of Science:
- Physics
- Granular Mechanics
- Fluid Dynamics
Background:
- Granular flows exhibit complex instabilities like vortices and clustering.
- Previous models were limited to nearly elastic systems, neglecting nonlinear dependencies.
Purpose of the Study:
- Determine critical length scales for instabilities in dense binary granular mixtures.
- Extend hydrodynamic analysis to strongly inelastic systems.
Main Methods:
- Linear stability analysis of Navier-Stokes (NS) granular hydrodynamic equations.
- Solution of the inelastic Enskog equation to NS order.
- Comparison with molecular dynamics (MD) simulations.
Main Results:
- Identified critical length scales for vortex and cluster instabilities.
- Accounted for nonlinear dependence of transport coefficients on restitution.
- Achieved excellent agreement between theoretical predictions and MD simulations for strong dissipation.
Conclusions:
- Navier-Stokes hydrodynamics is applicable to polydisperse granular flows.
- The model accurately predicts instabilities even with strong inelasticity and particle dissimilarity.
Related Concept Videos
02:34Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility
42.5K
Intermolecular forces are attractive forces that exist between molecules. They dictate several bulk properties, such as melting points, boiling points, and solubilities (miscibilities) of substances. Molar mass, molecular shape, and polarity affect the strength of different intermolecular forces, which influence the magnitude of physical properties across a family of molecules.
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
42.5K
01:28The Thermodynamics of Mixing
137
Mixing is a fascinating phenomenon in thermodynamics, particularly when considering the Gibbs energy of a mixture at constant temperature and pressure. This energy, denoted as G, tends to decrease during spontaneous mixing processes, offering insights into the composition changes that occur.Imagine two ideal gases, initially separated in different containers, with amounts nA and nB, respectively, both at a temperature T and pressure p. The chemical potentials of these gases have their 'pure'...
137
02:56Intermolecular Forces and Physical Properties
23.1K
23.1K
02:21Chemical and Solubility Equilibria
3.5K
The free energy change associated with dissolving a solute in a liter of solvent is called the free energy of a solution, ΔGsolution. The overall ΔGsolution is expressed as the balance of ΔGinteraction against the always-favorable free-energy of mixing, ΔGmixing. Solution formation is favorable if ΔGsolution is less than zero, whereas it is unfavorable if ΔGsolution is greater than zero. In short, for a solution to form and complete dissolution to take place,...
3.5K
02:39Entropy
25.7K
Salt particles that have dissolved in water never spontaneously come back together in solution to reform solid particles. Moreover, a gas that has expanded in a vacuum remains dispersed and never spontaneously reassembles. The unidirectional nature of these phenomena is the result of a thermodynamic state function called entropy (S). Entropy is the measure of the extent to which the energy is dispersed throughout a system, or in other words, it is proportional to the degree of disorder of a...
25.7K
01:23Stability of Equilibrium Configuration
998
Understanding the stability of equilibrium configurations is a fundamental part of mechanical engineering. In any system, there are three distinct types of equilibrium: stable, neutral, and unstable.
A stable equilibrium occurs when a system tends to return to its original position when given a small displacement, and the potential energy is at its minimum. An example of a stable equilibrium is when a cantilever beam is fixed at one end and a weight is attached to the other end. If the weight...
A stable equilibrium occurs when a system tends to return to its original position when given a small displacement, and the potential energy is at its minimum. An example of a stable equilibrium is when a cantilever beam is fixed at one end and a weight is attached to the other end. If the weight...
998