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Published on: November 26, 2019
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Flow states of two dimensional active gels driven by external shear
Wan Luo1,2, Aparna Baskaran3, Robert A Pelcovits4,5
1School of Engineering, Brown University, Providence, RI 02912, USA. Wan_Luo@brown.edu.
Soft Matter
|January 3, 2024
Summary
This study explores active gel behavior in channels under shear. Imposed shear can alter stability, leading to diverse flow states like unidirectional, oscillatory, and dancing flows in extensile gels.
Area of Science:
- Soft Matter Physics
- Fluid Dynamics
- Rheology
Background:
- Active gels exhibit complex flow behaviors driven by internal stresses.
- Understanding shear effects on active gel hydrodynamics is crucial for material science applications.
Purpose of the Study:
- To investigate the Couette flow of active gels in straight and annular channels under external shear.
- To characterize the distinct flow states and their transitions based on activity and shear rate.
Main Methods:
- Utilized a minimal hydrodynamic model for theoretical and computational analysis.
- Employed the finite element method to determine flow states.
- Conducted linear stability analysis for unconfined gels.
Main Results:
- External shear can stabilize or destabilize active gels, altering spontaneous flow tendencies.
- Extensile active gels exhibit unidirectional, oscillatory, and dancing nonlinear flow states.
- Contractile active gels show linear shear flow and a nonlinear unidirectional flow, potentially with boundary layers.
Conclusions:
- The study reveals diverse nonlinear flow regimes in active gels influenced by shear.
- Channel curvature in annular geometries affects transitions between flow states.
- Findings provide insights into the fundamental hydrodynamics of active soft materials.
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