Non-Linear Effects in Simple Shear Flow

We shall consider the case of shear stress when one of the components of the velocity gradient tensor has been specified and is constant, namely v 2 0. 

In order to achieve such a flow, it is necessary that the stresses applied to the system should be not only the shear stress a 12, as in the case of a linear viscous liquid, but also normal stresses, so that the stress tensor is 

The shear stress a 12 and the differences between the normal stresses a i -aoo and 022-033 are usually measured in the experiment. 

For the specified in this way motion, equation (9.2) defines, as was shown in Section 2.7.2, the non-zero components of the second-order moments 

According to the theoretical estimate of the exponent, zv varies from 1.5 (non-draining Gaussian coil) to 2.11 (draining coil with volume interactions). 

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