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Diameters of vortex spirals in three-dimensional turbulence
1Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Silver Street, CB3 9EW Cambridge, United Kingdom. rasmusse@maths.ox.ac.uk
Summary
Fully developed turbulence may not contain large spiral structures around vortex tubes as previously thought. This study explains numerical findings, showing spiral size rapidly shrinks with increasing Reynolds number.
Area of Science:
- Fluid dynamics
- Turbulence research
- Computational physics
Background:
- The existence of spiral-like vorticity distributions in fully developed turbulence has been debated.
- Numerical simulations have challenged the presence of these structures around vortex tubes.
Purpose of the Study:
- To provide an explanation for the discrepancies observed in numerical simulations of turbulence.
- To investigate the relationship between spiral structures and vortex tubes in turbulent flows.
Main Methods:
- Stability analysis of intense vortex tubes.
- Utilizing numerical results for high Reynolds numbers.
- Estimating spiral diameter as a function of Reynolds number.
Main Results:
- An explanation for the outcomes of numerical simulations is proposed.
- A method to estimate the characteristic diameter of the largest spirals was developed.
- The diameter of these spirals was found to decrease rapidly with increasing Reynolds number relative to the integral scale.
Conclusions:
- The findings reconcile theoretical proposals with numerical observations in turbulence.
- The study suggests that large-scale spirals diminish significantly in high Reynolds number turbulence.
- This work offers insights into the structure of vorticity in turbulent flows.