Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Shock Waves

Shock Waves

While deriving the Doppler formula for the observed frequency of a sound wave, it is assumed that the speed of sound in the medium is greater than the source's speed through it. When this condition is breached, a shock wave occurs.
When the source's speed approaches the speed of sound, constructive interference between successive wavefronts emitted by the source occurs immediately behind it. Initially, scientists believed that this constructive interference would result in such high pressures...

Turbulent Flow

Turbulent Flow

Turbulent flow is characterized by unpredictable fluctuations in velocity and pressure, which result in a chaotic fluid movement distinct from the orderly patterns of laminar flow. While laminar flow is governed by smooth, parallel layers with minimal mixing, turbulent flow exhibits highly irregular, three-dimensional patterns. This behavior arises due to instabilities in the fluid's velocity profile, and amplifies as the flow velocity increases. Minor disturbances, known as turbulent spots,...

Travelling Waves

Travelling Waves

A wave is a disturbance that propagates from its source, repeating itself periodically, and is typically associated with simple harmonic motion. Mechanical waves are governed by Newton's laws and require a medium to travel. A medium is a substance in which a mechanical wave propagates, and the medium produces an elastic restoring force when it is deformed.
Water waves, sound waves, and seismic waves are some examples of mechanical waves. For water waves, the wave propagation medium is water;...

Molecular Kinetic Energy

Molecular Kinetic Energy

The word "gas" comes from the Flemish word meaning "chaos," first used to describe vapors by the chemist J. B. van Helmont. Consider a container filled with gas, with a continuous and random motion of molecules. During collisions, the velocity component parallel to the wall is unchanged, and the component perpendicular to the wall reverses direction but does not change in magnitude. If the molecule’s velocity changes in the x-direction, then its momentum is changed. During the short time of the...

Propagation of Waves

Propagation of Waves

When a wave propagates from one medium to another, part of it may get reflected in the first medium, and part of it may get transmitted to the second medium. In such a case, the interface of the two mediums can be considered as a boundary that is neither fixed nor free.
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...

Deriving the Speed of Sound in a Liquid

Deriving the Speed of Sound in a Liquid

As with waves on a string, the speed of sound or a mechanical wave in a fluid depends on the fluid's elastic modulus and inertia. The two relevant physical quantities are the bulk modulus and the density of the material. Indeed, it turns out that the relationship between speed and the bulk modulus and density in fluids is the same as that between the speed and the Young's modulus and density in solids.
The speed of sound in fluids can be derived by considering a mechanical wave propagating...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Kinetic analysis of the pyrolysis of phenethyl phenyl ether: computational prediction of alpha/beta-selectivities.

The journal of physical chemistry. A·2007

Same author

Low-coherence self-referencing velocimetry.

Optics letters·2007

Same author

Low-coherence interferometric tip-clearance probe.

Optics letters·2003

See all related articles

Search research articles

Related Experiment Video

Updated: Jul 11, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids

Published on: December 4, 2017

Incomplete molecular chaos within dense-fluid shock waves.

Stefan Schlamp¹, Bryan C Hathorn

¹Institute of Fluid Dynamics, ETH Zurich, Sonneggstrasse 3, CH-8092 Zürich, Switzerland. schlamp@ifd.mavt.ethz.ch

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics

|October 13, 2007

Summary

Molecular dynamics simulations reveal long-range velocity correlations in shock waves of dense argon and nitrogen. These nonequilibrium effects challenge fundamental assumptions of the Boltzmann equation in fluid dynamics.

More Related Videos

Fast Imaging Technique to Study Drop Impact Dynamics of Non-Newtonian Fluids

Fast Imaging Technique to Study Drop Impact Dynamics of Non-Newtonian Fluids

Published on: March 5, 2014

Magnetically Induced Rotating Rayleigh-Taylor Instability

Magnetically Induced Rotating Rayleigh-Taylor Instability

Published on: March 3, 2017

Related Experiment Videos

Last Updated: Jul 11, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids

Published on: December 4, 2017

Fast Imaging Technique to Study Drop Impact Dynamics of Non-Newtonian Fluids

Fast Imaging Technique to Study Drop Impact Dynamics of Non-Newtonian Fluids

Published on: March 5, 2014

Magnetically Induced Rotating Rayleigh-Taylor Instability

Magnetically Induced Rotating Rayleigh-Taylor Instability

Published on: March 3, 2017

Area of Science:

Physics
Physical Chemistry
Computational Science

Background:

Shock waves are critical phenomena in fluid dynamics, studied for their complex behavior.
Understanding molecular-level interactions during shock compression is essential for material science.
The Boltzmann equation is a cornerstone for describing dilute gas dynamics, but its applicability to dense media under extreme conditions is limited.

Purpose of the Study:

To investigate molecular correlations during shock wave propagation in dense fluids.
To determine if nonequilibrium molecular motion extends beyond the immediate shock front.
To assess the validity of the Boltzmann equation's assumptions in dense shock-compressed materials.

Main Methods:

Large-scale molecular dynamics simulations were conducted for shock waves in dense argon and nitrogen.
The two-point molecular velocity correlation function was computed within planes parallel to the shock wave.
Simulations analyzed shock-normal and in-plane velocity components, as well as molecular rotation rates.

Main Results:

Long-range positive correlations (approx. 10 molecular radii, coefficient 0.05) were observed for velocity and rotation rates within the shock plane.
These correlations were exclusively present within the shock wave, absent upstream and downstream.
The observed correlations indicate a significant nonequilibrium state induced by the shock.

Conclusions:

Shock waves in dense fluids exhibit long-range molecular correlations not predicted by equilibrium theories.
These findings demonstrate a breakdown of the molecular chaos assumption inherent in the Boltzmann equation for dense shock phenomena.
Molecular dynamics simulations provide crucial insights into nonequilibrium processes at the nanoscale.