Related Experiment Video
Updated: Sep 13, 2025
08:01
The Diffusion of Passive Tracers in Laminar Shear Flow
Published on: May 1, 2018
8.7K
Turbulence spreading and anomalous diffusion on combs
Alexander V Milovanov1, Alexander Iomin2, Jens Juul Rasmussen3
1Max Planck Institute for the Physics of Complex Systems, ENEA National Laboratory, Centro Ricerche Frascati, I-00044 Frascati, Rome, Italy and , 01187 Dresden, Germany.
Physical Review. E
|August 1, 2025
Summary
This study introduces a model for turbulence spreading via wave interactions, revealing universal subdiffusive behavior. The findings suggest a unified mathematical framework for turbulence spreading and self-organization phenomena.
Area of Science:
- Physics
- Plasma Physics
- Nonlinear Dynamics
Background:
- Chaos spreading and turbulence spillover into stable regions are complex phenomena.
- Understanding the underlying transport mechanisms is crucial for predicting system behavior.
Purpose of the Study:
- To present a simple model for turbulence spreading and related transport processes.
- To derive and analyze the asymptotic behavior of wave field spreading.
Main Methods:
- Modeling transport via inelastic resonant wave interactions on a lattice.
- Utilizing a geometric "comb" construction for deriving transport equations.
- Applying continuous-time random walk (CTRW) and fractional-derivative equations.
Main Results:
- Wave field spreading universally exhibits subdiffusive behavior.
- Dispersion depends solely on the type of wave interaction (three- or four-wave).
- The comb model provides exact fractional indexes for kinetic equations.
Conclusions:
- Turbulence spreading and self-organization into banded flows/staircases share a common mathematical formalism.
- The comb approach offers a theoretical alternative to quasilinear theory.
- The model has implications for fusion plasma studies and is supported by observational and numerical evidence.
Related Concept Videos
01:24Turbulent Flow
281
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...
281
01:22Couette Flow
440
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...
440
01:07Laminar and Turbulent Flow
9.1K
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...
9.1K
01:09Turbulent Flow: Problem Solving
186
Carbonation is a process used to dissolve carbon dioxide gas in a liquid, commonly used in the production of carbonated beverages. Achieving efficient carbonation requires careful control of temperature, pressure, and flow conditions. By adjusting these parameters, carbonation efficiency can be maximized, producing a higher concentration of CO2 in the liquid.
Temperature is a key factor in CO2 solubility. In this case, the CO2 gas and the liquid are cooled to 20°C. Lower temperatures...
Temperature is a key factor in CO2 solubility. In this case, the CO2 gas and the liquid are cooled to 20°C. Lower temperatures...
186
03:48Behavior of Gas Molecules: Molecular Diffusion, Mean Free Path, and Effusion
29.5K
Although gaseous molecules travel at tremendous speeds (hundreds of meters per second), they collide with other gaseous molecules and travel in many different directions before reaching the desired target. At room temperature, a gaseous molecule will experience billions of collisions per second. The mean free path is the average distance a molecule travels between collisions. The mean free path increases with decreasing pressure; in general, the mean free path for a gaseous molecule will be...
29.5K
01:26Divergence and Curl of Magnetic Field
3.2K
The magnetic field due to a volume current distribution given by the Biot–Savart Law can be expressed as follows:
3.2K