Hybrid models for complex fluids with multipolar interactions

TL;DR

This paper introduces a novel hybrid dynamical model for complex fluids with multipolar interactions, incorporating microscopic effects and energy conservation, applicable to magnetized fluids and liquid crystal phases.

Contribution

It develops a hybrid moment closure approach inspired by Doi's model, capturing microscopic effects on order parameters in complex fluids with conserved energy.

Findings

Model applies to magnetized fluids with quadrupolar order.

Hybrid formulation extends to symmetry-breaking complex fluids.

Potential to analyze dynamics of cubatic phases in liquid crystals.

Abstract

Multipolar order in complex fluids is described by statistical correlations. This paper presents a novel dynamical approach, which accounts for microscopic effects on the order parameter space. Indeed, the order parameter field is replaced by a statistical distribution function that is carried by the fluid flow. Inspired by Doi's model of colloidal suspensions, the present theory is derived from a hybrid moment closure for Yang-Mills Vlasov plasmas. This hybrid formulation is constructed under the assumption that inertial effects dominate over dissipative phenomena, so that the total energy is conserved. After presenting the basic geometric properties of the theory, the effect of Yang-Mills fields is considered and a direct application is presented to magnetized fluids with quadrupolar order (spin nematic phases). Hybrid models are also formulated for complex fluids with symmetry breaking. For the special case of liquid crystals, the moment method can be applied to the hybrid formulation to study to the dynamics of cubatic phases.