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Updated: Jun 25, 2025
11:51
Visually Based Characterization of the Incipient Particle Motion in Regular Substrates: From Laminar to Turbulent Conditions
Published on: February 22, 2018
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Intermittency in the not-so-smooth elastic turbulence.
Rahul K Singh1, Prasad Perlekar2, Dhrubaditya Mitra3
1Complex Fluids and Flows Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan.
Nature Communications
|May 27, 2024
Summary
Elastic turbulence, a low Reynolds number phenomenon, shares similarities with Newtonian turbulence. Direct simulations reveal power-law energy spectra and evidence of intermittency, challenging previous assumptions.
Area of Science:
- Fluid Dynamics
- Polymer Physics
- Non-Newtonian Flows
Background:
- Elastic turbulence arises from elastic instabilities in viscoelastic fluids at low Reynolds numbers.
- Classical turbulence is well-understood in Newtonian fluids but its relation to elastic turbulence is less clear.
Purpose of the Study:
- To investigate the characteristics of elastic turbulence using direct numerical simulations.
- To compare elastic turbulence with Newtonian turbulence.
- To identify power-law spectra and evidence of intermittency in elastic turbulence.
Main Methods:
- Direct numerical simulations of viscoelastic fluid flow.
- Analysis of kinetic and polymeric energy spectra.
- Scale-by-scale energy budget calculations.
- Structure function analysis of velocity differences.
- Calculation of multifractal spectra from energy dissipation rates.
Main Results:
- Identified power-law spectra for kinetic energy (E(k) ~ k^-4) and polymeric energy (Ep(k) ~ k^-3/2), independent of Deborah number.
- Demonstrated a balance between viscous and polymeric terms in the momentum equation.
- Observed a non-trivial sub-leading contribution in velocity differences, indicating intermittency.
- Structure functions and energy dissipation rates provided evidence of multifractality.
Conclusions:
- Elastic turbulence exhibits more similarities to Newtonian turbulence than previously assumed.
- The findings support an intermittent and multifractal nature of elastic turbulence.
- Direct numerical simulations are effective in elucidating complex turbulent phenomena in viscoelastic flows.
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