Rheology in Region II The Effect of Texture Elasticity

Inspired by a mesoscopic theory for mixtures of immiscible liquids (Doi and Ohta 1991 see also Section 9.3.3), Larson and Doi (1991) have derived mesoscopic equations for polydomain nematics by multiplying the Leslie-Ericksen equation (10-13) by the director 

Here Utot is the sum of the viscous stress tr from Eq. (10-10) and the Frank distortional stress fromEq. (10-17), and (Kawaguchi 1996) 

The mesoscopic averages are designated by enclosure in the brackets ([ ]). The mesoscop-ically averaged order parameter S is defined as 

To understand the role of the terms ([nh]) and ([hn]), let us for the moment drop them from Eq. (11-24) thus 

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