Related Experiment Video
Updated: Aug 3, 2026
08:34
Visualization of High Speed Liquid Jet Impaction on a Moving Surface
Published on: April 17, 2015
Roughness-induced critical phenomena in a turbulent flow
1Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois, 61801-3080, USA.
Physical Review Letters
|February 21, 2006
Summary
Turbulent flows exhibit behaviors similar to critical phenomena. Accounting for boundary roughness is essential for a complete understanding of turbulence.
Area of Science:
- Fluid Dynamics
- Thermodynamics
- Statistical Mechanics
Background:
- Turbulent flows are ubiquitous in nature and engineering.
- Understanding turbulence remains a significant challenge in physics.
- Critical phenomena describe phase transitions in systems with many interacting components.
Purpose of the Study:
- To investigate the potential analogy between turbulent flows and critical phenomena.
- To reanalyze existing friction factor data for rough pipes.
Main Methods:
- Reanalysis of empirical friction factor measurements in rough pipes.
- Application of data collapse techniques analogous to those used for critical phenomena.
Main Results:
- Empirical evidence suggests a close analogy between turbulent flows and critical phenomena.
- Observed data collapse corresponds to Widom scaling near critical points.
- Boundary roughness plays a crucial role in the observed phenomena.
Conclusions:
- Turbulent flows share fundamental characteristics with critical phenomena.
- Explicitly accounting for boundary roughness is necessary for a comprehensive theory of turbulence.
- This analogy opens new avenues for turbulence research.
Related Concept Videos
01:07Laminar and Turbulent Flow
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 streamlines...
01:10Poiseuille's Law and Reynolds Number
Any fluid in a horizontal tube can flow due to pressure differences—fluid flows from high to low pressure. The flow rate (Q) is the ratio of pressure difference and resistance through a horizontal tube. The greater the pressure difference, the higher the flow rate. The flow resistance is expressed as:
01:28Irrotational Flow
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:
01:24Turbulent 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,...
01:18Boundary Layer Characteristics
When a fluid encounters a solid surface, a boundary layer forms due to the interaction between the fluid's motion and the stationary surface. This phenomenon is characterized by a thin region adjacent to the surface where viscous forces dominate, influencing the fluid's velocity profile. The development of the boundary layer begins at the leading edge of the surface and evolves as the fluid moves downstream.As the fluid flows over the surface, friction between the fluid and the wall slows down...
01:24General Characteristics of Pipe Flow II
When fluid enters a pipe, it first passes through the entrance region, where the velocity profile adjusts due to viscous effects. In this region, a boundary layer forms along the pipe walls and grows until it fully occupies the pipe's cross-section. Once the boundary layer merges, the flow becomes fully developed, with a steady velocity profile that remains consistent along the pipe's length.
The distance to reach a fully developed flow is called the entrance length and depends on the flow...
The distance to reach a fully developed flow is called the entrance length and depends on the flow...