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Updated: Oct 5, 2025
13:02
Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow
Published on: February 27, 2016
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λ-Navier-Stokes turbulence.
1Laboratoire de Physique de l'Ecole normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris 75005, France.
Summary
Researchers explored a modified Navier-Stokes model, altering energy cascade direction with a parameter λ. Near a critical point, kinetic energy diverges, reducing intermittency and revealing a new turbulent state.
Area of Science:
- Fluid Dynamics and Turbulence
- Computational Physics
Background:
- The Navier-Stokes equations describe fluid motion, but their complex behavior, especially in turbulent regimes, remains a significant challenge.
- Previous work introduced a parameter λ to the Navier-Stokes equations, allowing variation of homochiral vs. heterochiral interaction weights while preserving symmetries.
Purpose of the Study:
- To numerically investigate the impact of varying the parameter λ on energy cascade direction and turbulent properties.
- To explore the behavior of kinetic energy, energy spectra, and fluxes near a critical value of λ.
Main Methods:
- Numerical simulations of the modified Navier-Stokes equations with varying λ and Reynolds number (Re).
- Analysis of kinetic energy, energy spectra, and forward/inverse energy fluxes.
- Investigation of intermittency and fluctuations near the critical point.
Main Results:
- A critical value of λ was identified, leading to a change in energy cascade direction.
- Kinetic energy diverges with a specific scaling law as Re approaches the critical point.
- Energy spectra show an increased bottleneck effect with decreasing λ; fluxes exhibit large fluctuations near the critical point, and intermittency is reduced.
Conclusions:
- The study reveals a novel critical point in Navier-Stokes turbulence, characterized by diverging kinetic energy and reduced intermittency.
- A new stationary state with high-amplitude opposing fluxes is observed near this critical point.
- The findings suggest a potential statistical description of turbulence as an expansion around this critical point.
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