Power Law Model

The power law model is a common rheological model to quantify (typically) the Shear ThinningThe most common type of non-Newtonian behavior is shear thinning or pseudoplastic flow, where the fluid vis¬≠cosity decreases with increasing shear.shear thinning nature of a sample, with the value closer to zero indicating a more shear thinning material.  

It can be used to describe any material that shows power law behavior which is a proportional response of StressStress is defined as a level of force applied on a sample with a well-defined cross section. (Stress = force/area). Samples having a circular or rectangular cross section can be compressed or stretched. Elastic materials like rubber can be stretched up to 5 to 10 times their original length.stress to shear rate (or linear plot of viscosity vs shear rate). Technically, a power law index, n>1 denotes that the sample is Shear ThickeningWhile most suspensions and polymer structured mate­rials are shear thinning, some materials can also show shear thickening behavior where viscosity increases with increasing shear rate or shear stress.shear thickening; n<1 denotes that the sample is shear thinning and n=1 shows a Newtonian, viscous behaviour.

Note: do not use this model on data areas that show plateaus, i.e., the zero shear and infinite shear viscosities.

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