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08:01
The Diffusion of Passive Tracers in Laminar Shear Flow
Published on: May 1, 2018
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Conserving elastic turbulence numerically using artificial diffusivity
V Dzanic1, C S From2, E Sauret1
1School of Mechanical, Medical, and Process Engineering, Faculty of Engineering, Queensland University of Technology, QLD 4001, Australia.
Physical Review. E
|August 17, 2022
Summary
Researchers propose a new method to simulate elastic turbulence by limiting artificial diffusion to steep stress gradients. This approach avoids unphysical artifacts and accurately captures elastic turbulence features, improving simulation fidelity.
Area of Science:
- Fluid Dynamics
- Rheology
- Computational Physics
Background:
- Elastic turbulence simulations often use artificial stress diffusivity to manage steep polymer stress gradients.
- Previous methods employing this artificial diffusion have introduced unphysical artifacts, compromising simulation accuracy.
- These artifacts negatively impact the reliable simulation of viscoelastic flows.
Purpose of the Study:
- To propose a modified artificial diffusivity approach for simulating elastic turbulence.
- To demonstrate that localized artificial diffusion resolves simulation artifacts.
- To retain all essential features of elastic turbulence in numerical models.
Main Methods:
- Implementing a modified artificial diffusivity, localized to regions of steep stress gradients.
- Utilizing cellular forcing and four-roll mill flow problems for validation.
- Comparing results with direct simulations to assess artifact reduction and resolution requirements.
Main Results:
- The proposed modified artificial diffusivity effectively eliminates unphysical artifacts.
- All characteristic features of elastic turbulence are successfully retained in simulations.
- Results align with direct simulations, showing a shift from qualitative to quantitative impact of artificial diffusivity.
- The method requires significantly less numerical resolution.
Conclusions:
- Localized artificial diffusion is a superior approach for simulating elastic turbulence.
- This technique enhances the accuracy and reliability of viscoelastic flow simulations.
- The findings offer a more efficient and accurate path for studying elastic turbulence.
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