Vector nematodynamics with symmetry-driven energy exchange.

Area of Science:

• Physics
• Fluid Dynamics
• Materials Science

Background:

• Existing nematodynamic theories rely on Onsager's near-equilibrium relations.
• These theories face limitations in accurately describing complex fluid behaviors.

Purpose of the Study:

• To propose a novel theoretical framework for nematodynamics.
• To establish new relations between nematic orientation and fluid flow.
• To address limitations of near-equilibrium assumptions in current theories.

Main Methods:

• Developed a theory based on local symmetry between nematic alignment rotation and flow rotation.
• Utilized a vector-based theory with a variable modulus.
• Incorporated antisymmetric interactions between nematic alignment and flow.

Main Results:

• Established energy and momentum exchange mechanisms between nematic alignment and flow without near-equilibrium constraints.
• Avoided spurious instabilities often observed in existing models.
• Identified the underlying causes of these instabilities.

Conclusions:

• The novel approach provides a more robust description of nematodynamics.
• The theory offers insights into the behavior of active nematic systems.
• It resolves long-standing issues with theoretical instabilities.