Related Experiment Video
Updated: Jan 6, 2026
09:58
Investigating the Three-dimensional Flow Separation Induced by a Model Vocal Fold Polyp
Published on: February 3, 2014
8.8K
The Widom line in two- and three-dimensional fluids: Similarities and differences.
Yu D Fomin1, E N Tsiok1, V N Ryzhov1
1Vereshchagin Institute of High Pressure Physics, Russian Academy of Sciences, Kaluzhskoe shosse, 14, Troitsk, Moscow 108840, Russia.
The Journal of Chemical Physics
|November 3, 2025
Summary
Researchers studied supercritical fluids, revealing universal properties across different substances. They mapped the Widom line for 2D fluids and analyzed particle volumes, showing how structure changes with increasing density.
Area of Science:
- Thermodynamics
- Fluid Dynamics
- Materials Science
Background:
- Supercritical fluids exhibit unique properties between gas and liquid states.
- The Widom line signifies a crossover in thermodynamic behavior.
- Understanding fluid structure evolution is crucial for various applications.
Purpose of the Study:
- To investigate the structural evolution of supercritical fluids with increasing density.
- To determine the Widom line for a two-dimensional Lennard-Jones fluid and compare it to its 3D counterpart.
- To identify universal properties in supercritical fluids like water and methanol.
Main Methods:
- Computation of system properties across a wide range of thermodynamic parameters.
- Analysis of the Widom delta region to trace structural changes.
- Examination of Voronoi cell volume distributions and particle vs. system volumes.
Main Results:
- The Widom line was determined for a 2D Lennard-Jones fluid for the first time.
- Structural evolution from gas-like to liquid-like states was observed.
- Universal behaviors were identified in the supercritical Lennard-Jones system, methanol, and water.
Conclusions:
- Supercritical fluid behavior exhibits universal characteristics across different systems.
- The study provides insights into the structural transitions of fluids under supercritical conditions.
- The determination of the 2D Widom line offers a new benchmark for theoretical and computational studies.
Related Concept Videos
01:20Characteristics of Fluids
7.5K
When a force is applied parallel to the top surface of a solid, it resists the applied force due to the internal frictional forces between the layers of the solid known as shearing resistance. However, when the force is removed, the shearing forces restore the original shape of the solid. Other deformation forces also cause temporary changes in shape if the forces are not beyond a threshold magnitude. Solids tend to retain their shape, making the study of their rest and motion easier. Beyond...
7.5K
01:31Characteristics of Fluids
915
Fluids differ from solids primarily in their molecular structure and stress response. Solids have tightly packed molecules with strong intermolecular forces, maintaining their shape and resisting deformation. In contrast, fluids have molecules spaced farther apart with weaker forces, allowing them to flow and deform easily.
Fluids, which include both liquids and gases, are substances that deform continuously under shearing stress. For example, water and oil are liquids with molecules that can...
Fluids, which include both liquids and gases, are substances that deform continuously under shearing stress. For example, water and oil are liquids with molecules that can...
915
01:07Laminar and Turbulent Flow
10.4K
Fluid dynamics is the study of fluids in motion. Velocity vectors are often used to illustrate fluid motion in applications like meteorology. For example, wind—the fluid motion of air in the atmosphere—can be represented by vectors indicating the speed and direction of the wind at any given point on a map. Another method for representing fluid motion is a streamline. A streamline represents the path of a small volume of fluid as it flows. When the flow pattern changes with time, the...
10.4K
01:30Typical Model Studies
602
Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities.
602
01:06Divergence and Stokes' Theorems
3.4K
The divergence and Stokes' theorems are a variation of Green's theorem in a higher dimension. They are also a generalization of the fundamental theorem of calculus. The divergence theorem and Stokes' theorem are in a way similar to each other; The divergence theorem relates to the dot product of a vector, while Stokes' theorem relates to the curl of a vector. Many applications in physics and engineering make use of the divergence and Stokes' theorems, enabling us to write...
3.4K
01:17Steady, Laminar Flow Between Parallel Plates
752
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.
752