Topological defects lead to energy transfer in active nematics

Area of Science:

• Soft Matter Physics
• Fluid Dynamics
• Non-equilibrium Systems

Background:

• Active nematics are fluids with inherent orientational order, driven out of equilibrium by internal stresses.
• High active stress can lead to the proliferation of topological defects, a phenomenon termed defect chaos.

Purpose of the Study:

• To investigate energy transfer mechanisms in active nematics under different chaotic regimes.
• To characterize the scaling properties of energy transfer with respect to the active length scale.

Main Methods:

• Numerical simulations of low Reynolds number active nematics.
• Analysis of energy transfer between different length scales.
• Identification and characterization of defect chaos and bend wall chaos regimes.

Main Results:

• Defect chaos shows energy transfer from long to short length scales, driven by defect creation/annihilation.
• Energy transfer in defect chaos scales with the active length scale.
• Bend wall chaos exhibits energy transfer from short to long length scales due to extended bend walls.

Conclusions:

• Active nematics display distinct energy transfer behaviors in defect chaos and bend wall chaos regimes.
• The active length scale is a critical parameter governing energy transfer dynamics.
• Understanding these chaotic regimes is crucial for predicting active matter behavior.