Nonequilibrium Dynamics of Anisotropic Fluids

Abstract

In Chap. 9 we summarized methods for analyzing the equilibrium statistics of physical system, using Monte Carlo methods. While at equilibrium complex fluids may be isotropic or anisotropic, under the influence of external fields, all systems tend to become anisotropic (isotropic external fields are seldom). The anisotropy is induced by the external fields (flow field, magnetic field etc.) and must reflect the tensorial symmetry of the applied field. We have to deal with the coupling of tensors of different ranks, with important implications on Onsager reciprocal relationships, a topic discussed elsewhere. This chapter is concerned with the dynamics, in particular, the orientational dynamics of structured fluids subjected to orienting fields. The dynamics and anisotropy is properly modeled by using orientational distribution functions, their equations of change, and the corresponding equations of change for the moments (here, alignment tensors) of the distribution function. We restrict ourself to discuss the case of one-particle (single-link) orientational distribution functions.