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Updated: Aug 11, 2026
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Simultaneous Measurement of Turbulence and Particle Kinematics Using Flow Imaging Techniques
Published on: March 12, 2019
Imprint of large-scale flows on turbulence
A Alexakis1, P D Mininni, A Pouquet
1NCAR, Boulder, Colorado 80307-3000, USA.
Physical Review Letters
|February 21, 2006
Summary
Nonlinear interactions in hydrodynamic turbulence are nonlocal, involving wide-scale interactions. Energy transfer is local, but the cascade step depends on the integral scale, impacting turbulence modeling.
Area of Science:
- Fluid dynamics
- Turbulence research
- Computational physics
Background:
- Hydrodynamic turbulence is characterized by complex interactions across various scales.
- Understanding the locality of these interactions is crucial for accurate turbulence modeling.
- Previous models often assume locality, which may not fully capture turbulent phenomena.
Purpose of the Study:
- To investigate the spatial locality of nonlinear interactions in hydrodynamic turbulence.
- To analyze the scale-dependence of energy transfer in turbulent flows.
- To assess the impact of nonlocal interactions on turbulence modeling.
Main Methods:
- Direct numerical simulation (DNS) on a 1024^3 grid.
- Utilizing the Taylor-Green vortex as a flow forcing mechanism.
- Analysis of energy spectra and nonlinear triadic interactions.
Main Results:
- An inertial range with a constant energy flux and approximate Kolmogorov spectrum was observed.
- Nonlinear triadic interactions were found to be dominated by nonlocal components involving widely separated scales.
- The nonlinear energy transfer at each scale is local, but the cascade step is scale-independent and linked to the integral scale.
- Interactions with large scales contribute approximately 20% to the total energy flux.
Conclusions:
- Turbulent energy transfer exhibits both local and nonlocal characteristics, deviating from purely self-similar models.
- The scale-independent nature of the energy cascade step has significant implications for turbulence modeling.
- Findings suggest a link between interaction locality, intermittency, and the need for advanced modeling approaches in fluid dynamics.
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