Simulations of Transient Start-Up Shear Flows

In the following discussion, we will use normalized stresses denoting by additional + symbol the time-dependent shear and normal stresses. The absence of + symbols indicates the stresses in steady flow. 

It seems that the majority of thermotropic LCPs exhibit flow-aligning behavior. Thus, to describe the experimental observations for these polymers, the general viscoelastic nematodynamic theory [16,17] is used in our simulations with aligning assumption. 

the experimental data are denoted by dots and simulated curves by dashed fine. As seen, both the shear stress and the first normal stress difference display large and broad overshoots at yt fs 50. Since Titan has very rigid macromolecules, the evolution of texture is slow, and in turn the overshoot occurs at high value yt. 

Simulations of Relaxation after Cessation of Steady Flow 

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