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Microfluidic Devices for Characterizing Pore-scale Event Processes in Porous Media for Oil Recovery Applications
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Mapping two-dimensional polar active fluids to two-dimensional soap and one-dimensional sandblasting.
Leiming Chen1, Chiu Fan Lee2, John Toner3,4
1Department of Physics, College of Science, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China.
Nature Communications
|July 26, 2016
Summary
We found that active polar fluids and growing interfaces belong to the same universality class. This connection reveals robust, long-ranged correlations in 2D active matter systems.
Area of Science:
- Physics
- Soft Matter Physics
- Non-equilibrium Systems
Background:
- Active fluids and growing interfaces are distinct non-equilibrium systems.
- Each system displays unique non-equilibrium behavior compared to equilibrium systems.
Purpose of the Study:
- To demonstrate a surprising connection between active fluids and growing interfaces.
- To identify the universality class shared by these systems and related equilibrium systems.
- To analyze the properties of two-dimensional incompressible flocks.
Main Methods:
- Comparative analysis of the ordered phase of incompressible polar active fluids (2D, no momentum conservation) and the Kardar-Parisi-Zhang (KPZ) equation (1+1D).
- Identification of shared universality classes including 2D smectic liquid crystals and constrained 2D ferromagnets.
- Investigation of fluctuation correlations in 2D incompressible flocks.
Main Results:
- The ordered phase of 2D incompressible polar active fluids without momentum conservation belongs to the same universality class as the 1+1D Kardar-Parisi-Zhang equation.
- This universality class also encompasses 2D smectic liquid crystals and a specific type of constrained 2D ferromagnet.
- Two-dimensional incompressible flocks exhibit robust, universal long-ranged, anisotropic spatio-temporal correlations of fluctuations.
Conclusions:
- The established connection provides a framework for understanding active fluid behavior through equilibrium system analogies.
- Exact values for the anisotropy exponent (ζ) and roughness exponents (χx,y) characterizing flock fluctuations were determined.
- This research highlights the universality of physical phenomena across seemingly disparate systems.
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